Mary and her second husband, William Robertson settled in Kentucky, in Nelson Co. He died there in 1796. Mary is said to have later moved to Washington Co [which was formed from Nelson] where she left a will. Mary had no children.
Virginia Marriage database at MyHeritage gives the date of this marriage as 18 Jun 1759, Fauquier, VA
Jack Hardin, Jr. called this man William Robertson in his sage about the Hardin family. He stated that the man who lost his wife and children to the Indians on the 20th of March, 1780, was a brother to William. He never uses Robertson's first name. He also stated that Robertson's wife was some kin to the Hardins - if so, the connection has been lost.