There is a significant amount of documented information about Henley's daughter, Lydia, and the Thomases, including Lydia's descendants, in the book "Snead Notebook" by Elizabeth Shue on pages 50 through 64.
A recent effort to locate a copy of the book online was fruitless. Perhaps a copy is available to you at your local library. That is probably a longshot, but the best first step to access. If you can't get it that way, send me an e-mail at email@example.com
and I will send you a copy of the relevant pages either online or by postal mail as you wish.