Here is what I have on the family of William Neblett and his three wives. William Neblett appears to have been born in 1747 in Sussex Co., Vg. and died in 1835 in Franklin Co., Vg. His first wife was Ann Ragsdale, the daughter of Edward and Milly Ragsdale.
Children from this first marriage must have been: (1) Mary, who married Herman Bishop, (2) Francis, who married Nancy Elam, (3)Sally, who married John Morgan, (4) Patsy, who married Peter Ragsdale - these are my g-g-g-grandparents, (5)Nancy, who married William Ship, (6)Elizabeth, who married James Mitchell, and (7)Thomas, who married first Polly Williams, and secondly, Elizabeth Lovell.
On 18 April, 1792, William was married to Sally Love. Children born to this marriage must have been: (1)John, (2)Robert Caldwell, an M.D. who married Maria Ann Rowe, (3) William Saffold who married Mary Cheely, and (4) Rebekah who married John Ussery.
In 1803 William was married to Amy Williams. They had a daughter Martha. b. 1807, who is probably the Martha that married your William Copeland.
Hope this is helpful. Appreciate your sharing anything else you find on this family. Ed Emerson