She emigrated with her parents in the mid 1630s. Per "Currents of Malice..." by Persis McMillen:
William and Joanna Blessing Towne with their six eldest children left their home in Great Yarmouth, Norfolk County, England, where they had been born and bred. They crossed the Atlantic to Salem, Essex County, in the Massachusetts Bay Colony sometime during the 1630s. (the author lists the children's baptismal dates but does not cite a primary source for the immigration date).
Hanged as a witch, she died on 22 Sep 1692 at Proctor's Ledge, Gallows Hill, Salem, Massachusetts Bay. 
Accused of Witchcraft
Mary (Towne) Estey was executed for witchcraft in the Salem Witch Trials
Mary's sister, Rebecca (Towne) Nurse, older by thirteen years, had been accused and executed on 19 July 1692. Another sister, Sarah Cloyse, was also accused.
At the time of her questioning, Easty was about 58 years old and was married to Isaac Easty, with whom she had had seven children. Isaac owned and lived upon a large valuable farm. Her examination followed the pattern of most in Salem: the girls had fits, and were speechless at times, and the magistrate expostulated with her for not confessing her guilt, which he deemed proven beyond doubt by the sufferings of the afflicted.
"How far have you complied with Satan?" "Sir, I never complied with him but pray against him all my days. What would you have Easty do?" "Confess if you be guilty" "I will say it, if it was my last time, I am clear of this sin." During the exam, when Easty clasped her hands together, the hands of Mary Lewis, one of the afflicted were clenched and not released until Easty released her hands, and when she inclined her head, the afflicted girls cried out to have her straighten her neck, because as long as her head was inclined their necks were broken.
Easty was committed to prison after her examination. For a reason not disclosed in any of the remaining records, Easty, after spending two months in prison, was discharged on the 18th of May. She and her family believed she would now be safe from further accusations. They were wrong. The release seems to have been very distasteful to the afflicted girls, they became determined to not let the matter rest, and redoubled their energies to get her back into prison. On the 20th, Mary Lewis spent the entire day experiencing fits of unprecedented severity, during which time she said she was being strangled, and claimed "they will kill Easty out right." Several of the other afflicted girls claimed that they could see the apparition of Easty afflicting her, and people came from all around to see the fits. That evening a second warrant was issued for Easty's arrest. At midnight, after experiencing two days of liberty and being reunited with her family, Easty was rousted from her sleep by the marshall, torn from her husband and children, and taken back to prison where she was loaded with chains. Once Easty was back in prisons with chains, Lewis's fits stopped.
She was tried, found guilty and condemned to death on 9 September.
“...eighteen pounds of iron for fetters, for making four pair of iron fetters and two pair of handcuffs, and putting them on the legs and hands of Goodwife Cloyse, Easty, Bromidg, and Green...(bill of expense)
While in jail, she petitioned the court:
The Humble Petition of Mary Easty unto his Excellency Sir William Phips, and to the Honored Judge and Bench now sitting in Judicature in Salem, and the Reverend Ministers, humbly showeth, that, whereas, your poor and humble petitioner, being condemned to die, do humbly beg of you to take It In yonr judicious and pious consideration that your poor and humble petitioner, knowing my own Innocency, blessed be the Lord for It ! and seeing plainly the wiles and subtility of my accusers by myself, cannot but judge charitably of others that are going the same way of myself, If the Lord steps not mightily in. I was confined a whole month upon the same account that I am condemned now for, and then cleared by the afflicted persons, as some of Your Honors know. And in two days' time I was cried out upon them, and have been confined, and now am condemned to die. The Lord above knows my Innocency then, and likewise does now, as at the great day will be known to men and angels. I petition to You Honors not for my own life, for I know I must die, and my appointed time is set ; but the Lord he knows it is that, if it be possible, no more innocent blood may be shed, which undoubtedly cannot be avoided in the way and course you go in. I question not but Your Honors do to the utmost of your powers in the discovery and detecting of witchcraft and witches, and would not be guilty of innocent blood for the world. Bnt, by my own innocency, I know you are in the wrong way. The Lord in his infinite mercy direct you in this great work, if it be his blessed will that no more Innocent blood be shed, I would humbly beg of you, that Your Honors would be pleased to examine these afflicted persons strictly, and keep them apart some time, and likewise to try some of these confessing witches; I being confident there is several of them has belled themselves and others, as will appear, if not in this world, I am sure In the world to come, whither I am now agoing. I question not but you will see an alteration of these things. They say myself and others having made a league with the Devil, we cannot confess. I know, and the Lord knows, as will . . . appear, they belie me, and so I question not but they do others. The Lord above, who is the Searcher of all hearts, knows, as I shall answer It at the tribunal seat, that I know not the least thing of witchcraft ; therefore I cannot, I dare not, belie my own soul. I beg Your Honors not to deny this my humble petition from a poor, dying, innocent person. And I question not but the Lord will give a blessing to your endeavors."
Hanged as a witch, she died on 22 Sep 1692 at Proctor's Ledge, Gallows Hill, Salem, Massachusetts Bay. 
Cotton Mather would later write of September 22nd, 1692, the deadliest day of the Salem witch trials, thatDeacon Nicholas Noyes had said out loud ‘what a sad thing it was to see eight firebrands of Hell hanging there.’”
After her death, her husband spent almost twenty years trying to clear her name; ultimately, in 1711, the verdict was annulled and the court granted him twenty pounds in acknowledgement of the injustice of the previous decision.
Further Analysis of Mary Easty's Salem Witch Trial Experience
Mary Easty was not a member of Salem Town or Village, but a resident of Topsfield, a settlement just north of the Village. Animosity had festered between members of Salem Village and Topsfield since 1639 when the General Court of Massachusetts granted Salem permission to expand northward in the direction of the Ipswich River, but then only four years later the same court authorized inhabitants of another Village, Ipswich, to found a settlement there. As land became scarcer, quarrels regarding boundaries between the settlement to become known as Topsfield and Salem went on for a century. The Putnams of Salem Village embodied this battle in their quarrels with the Nurse family, Mary Easty's brother-in-law. According to Boyer and Nissenbaum in Salem Possessed, considering the bitterness between these families, it can be seen as no coincidence that the three Towne sisters, Rebecca Nurse, Sarah Cloyce and Mary Easty, were all daughters and wives of Topsfield men eventually to be persecuted by Putnam women in 1692 on behalf of Putnam men.
More interesting than the accusations against Easty is her experience during the trials. She was accused on April 21, examined on the 22nd, and imprisoned after denying her guilt. During her examination, Magistrate John Hathorne aggressively questioned Easty, or more accurately, tried to lead her to a confession by the following line of questioning:
"How can you say you know nothing when you see these tormented [girls], & accuse you that you know nothing?" "Would you have me accuse myself?"
"Yes if you be guilty."
"Sir, I never complied but prayed against [the devil] all my dayes... I will say it, if it was my last time, I am clear of this sin." (SWP I 120)
In a surprising moment, Hathorne, clearly affected by the convincing manner with which Easty spoke, turned to the accusers and asked, "Are you certain this is the woman?" This question acted as a symbol for the accusers to release their full energy into tormented fits. Hathorne was now convinced and imprisoned Easty. The girls, however, seemed not to be fully convinced of their own accusations. Perhaps due to pressure from community around Easty, all of the accusers, except Mercy Lewis, began to back off their claims and Easty was released from jail on May 18.
The details of what happened next provide undeniable clues about the power of the accusers and the impossibility of conducting a fair juridical process. After Easty's release, Mercy Lewis fell into violent fits and appeared to be approaching death. Mercy Lewis later explained that Easty was tormenting her, and "said [Easty] would kill [Lewis] before midnight because she did not cleare hir so as the Rest did." (Salem Witchcraft Papers, I: 124) Mary Walcott, Abigail Williams and Ann Putnam were brought to her bedside in an effort to discover who was tormenting Mercy. Along the path to the Mercy's house, Ann and Abigail explained that they saw Easty's specter tormenting Mercy, strongly suggesting a collaboration effort had already taken place before Mercy began her torments. Frances Hill in A Delusion of Satan calls this episode a propaganda scheme to show doubting Villagers the dire consequences of freeing witches from jail. Mercy and four others cried out against Easty on May 20. Mercy's fits did not cease until Easty was back in prison in irons demonstrating the effective power of the accusers.
While Easty remained in jail awaiting her September 9 trial, she and her sister, Sarah Cloyce, composed a petition to the magistrates in which they asked, in essence, for a fair trial. They complained that they were "neither able to plead our owne cause, nor is councell allowed." They suggested that the judges ought to serve as their counsel and that they be allowed persons to testify on their behalf. Easty hoped her good reputation in Topsfield and the words of her minister might aid her case in Salem, a town of strangers. Lastly, the sisters asked that the testimony of accusers and other "witches" be dismissed considering it was predominantly spectral evidence that lacked legality. (Salem Witchcraft Papers, I: 303) The sisters hoped that the judges would be forced to weigh solid character testimony against ambiguous spectral evidence. The petition did not change the outcome of Easty's trial, for she was condemned to hang on September 17th. But together with her second petition, Easty had forced the court to consider its flaws.
Easty's second petition was written not as a last attempt to save her own life but as a plea that "no more innocent blood may be shed." (SWP I :304) She concedes saying that the court had the best of intentions, but only more innocent deaths would occur if the court continued its practices, for she like many others could not "belie [their] own soul." She proposes two strategies for the court in to use when determining witchcraft: First, she asks that the accusers be kept apart to see if under such circumstances they would all tell the same experiences. If they were able to give similar credible accounts of their spectral experiences then any doubt would be removed as to the guilt or innocence of the person on trial. This proposal brings to mind Thomas Brattle's observation in his famous Letter of October 8, 1692 that the accusers, when not claiming to be attacked by specters, were otherwise in good health. Easty was obviously not the only skeptic of the accusers' spectral torments. Secondly, Easty proposed that all confessing witches be brought to trial as well as those confessing innocence. Rosenthal writes in A Salem Story that in an atmosphere of rising doubt, "for the court to ignore Easty's challenge would be to acknowledge to the critics that the proceedings were fatally flawed - that the hunt was not really for witches after all but for validating the court."
Easty was hanged on September 22, 1692. Her demeanor at Gallows Hill is documented by Calef: "when she took her last farewell of her husband, children and friends, was, as is reported by them present, as serious, religious, distinct, and affectionate as could well be exprest, drawing tears from the eyes of almost all present." Easty challenged the court to no personal avail, but she exposed the weakness of the court for the benefit of others.
She died on a chill and rainy day.
17 October 1710, Convictions Reversed, The General Court of Massachusetts Bay, An act, the several convictions, judgments, and attainders be, and hereby are, reversed, and declared to be null and void.
17 Dec 1711, Compensation to Survivors, Governor Dudley, GOVERNOR OF MASSACHUSETTS BAY, approved compensation to such persons as are living, and to those that legally represent them that are dead [For Mary Easty, £20]
28 Aug 1957, No Disgrace to Descendants, General Court of Massachusetts, ...such proceedings, were and are shocking, and the result of a wave of popular hysterical fear of the Devil in the community, and further declares that, as all the laws under which said proceedings...have been long since abandoned and superseded by our more civilized laws, no disgrace or cause for distress attaches to the said descendants or any of them by reason of said proceedings.
31 Oct 2001, Additional Victims Included, Massachusetts Senate and House of Representatives in General Court, AN ACT RELATIVE TO THE WITCHCRAFT TRIAL OF 1692, chapter 145 is hereby further amended by adding Bridget Bishop, Susannah Martin, Alice Parker, Margaret Scott and Wilmot Redd.
It may be possible to confirm family relationships with Mary by comparing test results with other carriers of her mitochondrial DNA.
Mitochondrial DNA test-takers in the direct maternal line: