To clear up the age of Martha Hayes daughter of Mary Maria Hayes nee De Knight/Danight. When Martha remarries after the death of her first husband Andrew Whitehead (1832, aged 64), she tells the minister that she is 50 years old. She married a young police clerk from the township of Brighton Tasmania, which is not very far from where she lived with her first husband Andrew, at Herdsman Cove. The marriage of Bernard (Barnard) Williamson to Martha Whitehead occurred on the 7th January 1836, his age is recorded as 20, her's 50. The "Cornwall Chronicle" reported the marriage in their 16th January 1836 edition.
More often than not an older woman would put her age down when there was such a big age difference, but in Martha's case I don't think she did .... I think she was being honest. So, I believe she was born sometime in 1785, or very early in 1786.
Her death on 14th May 1871 she is recorded as being 84, she died at the home of her daughter Mary Devine nee Whitehead, "The Lea", Kingston, Tasmania. The "Mercury" reported that except for one woman, Martha Williamson was the last of the first settlers.