Robert is listed as a pioneer immigrant to New Zealand. From his death notice his birth year can be calculated (Oct 14 1886 aged 49 = 1837.) It can be seen on his gravestone.
Immigration in New Zealand Mr. Isaac and Mrs. Aroa and 3 children, and grown children M. A. [Mary Ann] Aroa and Mr Robert Aroa emigrated to New Zealand in 1855 on the ship Maori. 
NOTE: He is referred to as the brother-in-law of Mr Denis Broughan, which makes him the sibling of Nancy Mary. It should be noted that adult children are shown in shipping lists separately.
The 1851 Census  lists parents and siblings as residing at Byers Green, Durham. His father Isaac is a blacksmith, having 3 children, Nanny (8), Sarah (6) and Isaac (1) at home.
In the same census, there is a Robert Aroa (listed as Arah) aged 14, a servant at the Binchley Crag Farm only a short distance from Byers Green. His birth place is listed as Westmorland.
Furthermore, his sister Mary Ann Aroa (listed as Array) aged 16, is a servant at a house in Byers Green.
New Zealand property From The Colonist 9th September 1859 Robert Aroa - District—The Clarence. Bounded to the northward by the dividing range between the rivers Clarence and Awatere; southward by the river Clarence; eastward by the lake McRae and the run applied for by George Williams, Esq.; mid extending as far westward or up the river Clarence as will make ten thousand acres. Deposit paid—£l5.
Marriage In New Zealand on July 27 1865 Robert Aroa and Ellen Soper were married
Children Robert and Ellen had 9 children .
October 14 Marlborough Express published a more detailed account of Robert's accident: 
A FARMER KILLED It is with much regret that we announce the death of Mr Robert Aroa, the widely known and respected farmer at the "Blind River”, who was the victim of a fatal accident last night about 6 o'clock in the Maxwell Road. Mr Aroa had been transacting his usual business in town, and was on his way (as was customary to him) to the residence of his brother-in-law, Mr Denis Broughan, New Renwick Road. His dray was heavily loaded, and he was driving. As he passed the South Star Hotel he was seen to light his pipe, but when near to Mr Douslin's house a sudden jolt jerked him off the seat and down between the stanchions of the dray on to the ground, a wheel of the heavily laden dray passing over his chest. The poor fellow raised himself once from the ground, but never spoke again, and owing no doubt to rupture of internal organs, there was great hemorrhage from the mouth and he died in a few minutes.
The body was removed to the South Star Hotel, and messengers rode off at once to Mr Broughan's house, and subsequently to acquaint the family of the deceased at the Blind River with the awful news.
Mr Aroa was in his 50th year, and leaves behind him a widow and nine young children. Mr Douslin and other gentlemen who happened to be near when the accident occurred picked him up, and procured the immediate attendance of Dr Nairn, but before that gentleman could arrive life had passed away.
Mr Aroa was much respected by all who knew him, and there will be universal sympathy for those he leaves behind. He was connected by marriage with Mr Wm. Atkinson of Rangiora as well as with Mr Denis Broughan. Mr Richard Beale of the New Road was also a brother-in-law. The deceased came out to New Zealand about 30 years ago, and had been at the Blind River for upwards of 25 years. Deceased was a very old member of the Loyal Marlborough Lodge of Odd Fellows.
As to the immediate cause of the accident it is surmised that the horses made an attempt to turn the corner by Mr T. Horton's house, and that the sudden wrench threw deceased from his seat.
Inquest 15 October 1886, the Marlborough Express reported fully on Robert's inquest:  THE INQUEST. Mr Allen, R.M., Coroner, held an Inquest this morning, at the Court House, on the body of Mr Robert Aroa, who met with a fatal accident last evening. The Jury consisted of Messrs T. Watson (who was elected foreman), Patrick Maher, C. W. Badge, J. H. Marplo, E. Mead, Joseph Nancarrow, and W. T. Sherwood. The Coroner said that Dr Nairn had informed him that from the external marks on the body he could not tell the exact cause of death— whether from rupture of the heart, rupture of the lungs, or any other vital part. It was for the jury to say whether a postmortem examination should be made.
The Foreman intimated that the jury did not deem it necessary, for if it were shown that the death was caused by the dray going over the chest, it mattered little which of the vital parts was ruptured. The Jury retired to the South Star to view the body, and on their return Sergt. White called the following evidence:
E. G. Walsh deposed that he last saw deceased at half past 5 o'clock p.m., when he had evidently been drinking but was quite capable of taking charge of the horse and dray. He drew up at the door of Fell's store for some goods, the total weight of which was about 7 cwt. It was a heavy dray. Witness well knew deceased as a sober respectable man and had never seen him the worse for drink.
Morgan O'Flaherty deposed that he last saw deceased at half past 5 or 20 minutes to 6 o'clock, at Litchfield's corner. He was not very noticeably under the influence of liquor, and was able to take care of the horse and dray. The latter was open at the front, and he sat on the near side corner holding the reins. Witness knew deceased as a sober man.
Thomas Parkinson, residing at the South Star Hotel, last saw deceased driving past there in a dray. He was half leaning on some wool bales and half sitting. He was smoking. Deceased did not call in at the South Star. The reins were tied on to the guard iron, and the horse was going on at an average walk. Came to the conclusion that deceased was sober, and watching the horse. It was a one-horse heavy dray.
Horace Douslin said that about five minutes past six last evening he and his brother heard the horse start, and saw deceased hanging on to the reins and running alongside the dray. He held on for some ten yards and then seemed to trip, and fell just in front of the wheel which passed over his body, He was on the near side of the dray. After he fell he was not dragged. Witness ran out and picked him up. Deceased was bleeding at the mouth and nose, and there was a large pool of blood on the ground. He never spoke or moved or made any noise. Witness got some water and bathed his head, and removed him to the side of the road. A cab took him away to the South Star. When witness first saw it the horse appeared to be bolting. After the accident it went on ahead and was stopped some distance up the road. Dr Nairn came up. No one was in the dray with deceased.
W. M. Heywood said that when he first saw deceased he was hanging on by the reins, into which he had evidently fallen. The reins were fastened on to the guard iron, and he was trying to regain his footing. The horse was just in a canter at the time. Witness was not near enough to stop it. Deceased at last fell in front of the wheel, which passed over him from his left side to the right. He tried to get up but rolled over. Witness managed to stop the horse with some difficulty, and in the meantime other people rendered assistance to deceased.
John Nicholson stated that deceased got on his dray at Litchfield's corner a few minutes before six o'clock, and was quite able to take charge of his horse and dray. He had previously got two bags of sugar, and two parcels from Litchfield's store, the weight being about 11/2 cwt.
Dr Nairn deposed that about 10 minutes to 6 o'clock he saw deceased get off his dray to speak to a woman in the road. He pushed her perambulator for her for about 20 yards, and then went after her down a by-road, leaving the dray standing. Witness saw nothing more of deceased until he was sent for about 10 minutes past 6 o'clock. Found him lying on the road-side, quite warm, and apparently about five minutes dead. Saw him removed to the South Star. Dr Nairn then described the result of a post mortem examination which he made, the jury having, after viewing the body, expressed a desire to have one made. He found the breast bone completely fractured, and nine ribs on the right side broken. The right lung was much lacerated, and contained a great quantity of blood. The other organs were sound. The injuries were quite sufficient to cause death.
Constable Ward said he saw deceased in front of Fell's store at 25 minutes past 6 o'clock. He was able to take charge of his horse and dray. Next saw deceased lying dead in the Maxwell Road.
The Jury returned the verdict of "Accidental Death."
Funeral Notice 
Funeral.— The Oddfellows are summoned to meet at their lodge room at 2 o'clock to-morrow afternoon, to attend the funeral of the late Mr Aroa, a member of the Order. The funeral will leave Mr Denis Broughan's residence at a quarter to 3 o'clock.
Funeral Report 
The attendance of the friends of the late Mr Robert Aroa at his funeral yesterday was one of the largest known in Marlborough for many years. The procession as it moved from the residence of Mr Denis Broughan, New Renwick Road, to the Taylor Cemetery was a quarter of a mile long.
According to the Robinson Family Tree at myheritage.com, there are other children.
Conclusion - Mary Jane (Aroa) Robinson is not one of his children.
Conclusion - Ellen Aroa is not one of his children.
Conclusion - George Francis Aroa is not one of his children.
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