My understanding is that he came to own Nancy through inheritance from his mother. The 4 children of Nancy have been reported as Lee’s children by some, but at this divide, I don’t think that can be sustained or denied with evidence other than hearsay testimony by persons long dead.
“My understanding is that he came to own Nancy through inheritance from his mother”
Small surprise that you would have little actual knowledge of his history since that isn’t as useful to you as disparagement and scurrilous rumor. But then that’s just you expressing your character through your writing.
Lee’s father was famously bankrupt when Lee was a small child. His father died when Lee was 11 and Lee and his mother went to live with relatives. They had no assets and no inheritance, other than the ones in your well fertilized imagination.
The White House property belonged to the Washington-Custis family and Nancy and her family came with it.