Hello Carole
I am currently writing a two part book on the early Romany Boswell family 1650-1810. I've collected around 350 different sources on the family for those dates, and made a rough attempt to make some sense of them and put them into some sort of framework.
First thing I would add to what has been said is ages on burial were typically inflated in the Romany community, especially amongst the older more high status families such as the Boswells, Hearn, Lovells, Smiths etc. This is partly because a strong cultural difference existed, age was viewed with prestige in the community, whereas some non Gypsies in comparison might be more inclined to knock years off themselves on census records etc, the tendency is almost always the opposite amongst Romanies. Then of course most only had a vague idea of their exact age anyway, so accuracy is rare to begin with.
Woodfine/Woodbine Smith (or his family) did claim an age of 102 for him at death, but he was actually more likely around 87, he had been baptised the son of Nehemiah Smith and Elizabeth, at Weedon Lois, Northamptonshire on 6th March 1780. This matches well with his eleven known children born to Sarah 1801-1824. His own looseness with his age is shown by the fact he gave his age as 84 in October 1857, three years younger than his true age, but probably his best guess, but just four years later claimed to the 1861 census takers he was 96, so in his own mind he'd aged himself twelve years in just four!
Sarah is likely to have been a similar sort of age to Woodfine, born circa 1780. I don't have a baptism for a Sarah around that time, and certainly there are many children still missing from the record who were either baptised, but the record has yet to be found or were not baptised at all (though church baptism in the community was a lot more common then is sometimes made out).
This record is interesting though
Vagrants pass for Cornation Boswell and child, Sarah, from North Wraxall, Gloucestershire to Bottlesford otherwise Bulford, Wiltshire, 8th July 1780.
I would say this is very likely the wife of Lawrence Boswell, as I don't have any other Cornation Carnation in records at that time, and she had links to Wiltshire. Her marriage, license of October 1774 describes her as Carnation Boswell ‘of Devizes, Wiltshire’.
These are the first three children I have baptised to Lawrence and Carnation:
Robert Boswell, son of Lawrence Boswell and Carnesia 'Travellers' baptised at St Mary the Virgin, Hatfield Broad Oak, Essex on 19th May 1776.
Azgad Boswell, son of Laurence Boswell and Carnatia (or Constantia), 'Travellers', baptised at Cottered, Hertfordshire on 23rd November 1777.
Scamper Boswell, son of Lawrence Boswell and Carnation, baptised at Great Wymondley, Hertfordshire, on 27th January 1782.
So certainly Sarah the child on the vagrants pass could have been a young infant born around 1779/1780, which would explain why she could not be parted with the mother, whereas the elder children, if still alive, were left elsewhere.
There is also the fact that Sarah and Woodfine married at Hillmorton, Warwickshire in 1811. Lawrence and his family were travelling the same region in that era. Lawrence's 25 year old son was buried at Knowle, Warwickshire, about 25 miles away in January 1815, and Lawrence himself was later laid to rest there with him in June 1833, his age then given as 75.
It is not a certain identification but my best bet would be that Sarah the wife of Woodfine, was the same as Sarah the daughter of Lawrence.