Katherine White was the daughter of Alexander White of Sturton-le-Steeple, Nottinghamshire, England, born before 1580. Soon after her father's death (will proved May 6, 1596) Catherine was married to George Leggat, member of a yeoman family long settled at Sturton, and soon they had a daughter named Marie. Before many years had passed Catherine lost her husband and in course of time she married John Carver.
"The wife of John Carver, the first governor of Plymouth Colony. Katherine was a prominent woman in the English Separatist church in Leiden, and it was not until their marriage that John Carver became a member of the separatists. It is not certain when they were married, but the records state that Katherine Carver witnessed the betrothal of Roger Chandler and Isabella Chilton on 22 May 1615, so it must have taken place sometime before May 1615. Katherine's father was Alexander White of Sturton-le-Steeple, Nottinghamshire. Her siblings were also active members of the church. Her sister Bridget was married to the Leiden congregation's pastor John Robinson. Her sister Jane was married to Randall Thickens, sister Frances was married to Francis Jessop, and her brother Roger White was also married to a prominent church member. Katherine and John Carver had no surviving children. They are known to have had one child but it died in infancy on 11 November 1617. Both John and Katherine died the spring of 1621 having left behind no descendants."
In 1599 she is mentioned in her mother's will as being married to a Mr. Leggett and their daughter Marie of age less than ten. Katherine's husband died and she remarried, perhaps around 1616, to John Carver. They buried a child in November 1617 in Leiden.
Her husband John organized the Mayflower voyage. Both Katherine and John Carver came on the Mayflower to Plymouth in 1620. They survived the harsh winter of 1620-21. The following spring John died while working in the fields. Katherine died within five or six weeks of John.
Since the Carvers had no surviving children, John Howland, their indentured servant, is thought to have inherited their estate. It has been said that he immediately 'bought his freedom' but no record has survived.
She was a widow of George Leggatt and eldest daughter of eight children of Alexander White and his wife Eleanor of Sturton-le-Steeple,
Katherine Carver witnessed the betrothal of Robert Cushman and Mary Singleton. Robert Cushman was a deacon of the Leiden church and would play an important part, as chief agent for the church, in preparing the Mayflower for her voyage.
On November 11, 1617, at St. Pancras in Leiden, Katherine Carver buried a child, probably an infant.
The following is quoted from William Bradford's Mayflower passenger list, written some 30 years after the landing. 
mr. John Carver. Kathrine his wife. Desire Minter; & 2. man-servants, John Howland Roger Wilder. William Latham, a boy, & a maid servant. & a child yt was put to him called, Jasper More. 
These bening aboute a hundred sowls came over in this first ship: and began this worke ... I have thought it not unworthy my paines, to take a view of the decreasings, & Increasings of these persons, and such change as hath pased over them, & theirs, in this thirty years.
mr. Carver and his wife, dyed the first year, he in ye spring, she in ye somer; also his man Roger, and ye litle boy Jasper, dyed before either of them, of ye commone Infection. Desire Minter, returned to her friend & proved not very well, and dyed in England. His servant boy Latham after more then .20. years stay in the country went into England; and from thence to the Bajamy Ilands in ye west Indees; and ther with some others was stavred for want of food. His maid servant maried, & dyed a year or tow after here in this place. His servant John Howland maried the doughter of John Tillie, Elizabeth, and they are both now living; and have .10. children now all living and their eldest doughter has .4. children and ther .2. doughter, one, all living and other of their children mariagable, so 15. are come of them.
Of these 100 persons which came first over, in this first ship together; the greater halfe dyed in the general mortality; and most of them in .2. or .3. monthes time. And for those wich survifed though some were ancient & past procreation; & others left ye place and cuntrie. yet of those few remaining are sprunge up above. 160 persons; in this .30. years. And are now living in this present year. 1650. besids many of their children which are dead and done not within this account.
And of the old stock, (of one, & other) ther are yet living this present year. 1650. nere .30. persons. Let the Lord have ye praise; who is the High preserver of men. 
↑ The Great Migration Begins: Immigrants to New England 1620-1633, Volumes I-III. (Online database: AmericanAncestors.org, New England Historic Genealogical Society, 2010), (Originally Published as: New England Historic Genealogical Society. Robert Charles Anderson, The Great Migration Begins: Immigrants to New England 1620-1633, Volumes I-III, 3 vols., 1995). pp320-322
Bradford, William. History of Plymouth Plantation (Massachusetts Historical Society, 1856) p. 447 "8 [persons] M. John Carver; Kathrine, his wife; Desire Minter; & . 2. man-servants, John Howland, Roger Wilder; William Latham, a boy; & a maid servant, & a child yt was put to him, called Jasper More." p. 450. "M. Carver and his wife dyed the first year; he in ye spring, she in ye somer; also, his man Roger and ye litle boy Jasper dyed before either of them, of ye commone infection. Desire Minter returned to her freinds, & proved not very well, and dyed in England. His servant boy Latham, after more then 20 years stay in the country, went into England, and from thence to the Bahamy Ilands in ye West Indies, and ther, with some others, was starved for want of food. His maid servant maried, & dyed a year or tow after, here in this place." "15. [persons]His servant, John Howland, maried the doughter of John Tillie, Elizabeth, and they are both now living, and have 10. children, now all living; and their eldest daughter hath 4. children. And ther 2. daughter, 1. all living; and other of their children mariagable. So 15. are come of them."
Bradford, William, 1590-1657. Of Plimoth Plantation: manuscript, 1630-1650. State Library of Massachusetts "List of Mayflower Passengers." In Bradford's Hand.