Elizabeth Abernathy was born 20 May 1730 in what was then Prince George County VA. She was Baptized 30 Sep 1730. She is listed in Chamberlayne's transcription of the Vestry Book and Register of Bristol Parish VA (p. 276) as daughter of Robert and Mary Abernathy. Robert's will was dated 31 Jan 1772 in what was then Tryon County NC, but Elizabeth (Abernathy) Williams is not, for some reason, mentioned, which she no doubt would have been if she was still alive.
I cannot verify that this Elizabeth Abernathy was the one who married Charles Williams, since I have as yet not found any marriage record in Virgina to that effect and have no other contemporary evidence to support the possibility. Although quite a number of people seem to have a belief in it having happened.