Thank you very much for your response. I am familiar with much of what you said, especially William's marriage to Nancy Mercer and the marriage of William's son, James, to Lovey Mercer. My notes show that Martin Richards and George Washington Richards were two of seven children from William's marriage to Nancy.
I know that William was married before and had three sons: James (b abt 1776), John (b abt 1778), and Willis (b. 1784). I am descended through Willis and am in contact with several other descendents of William who have collected a lot of evidence on his line. We're now pretty sure the reference we saw to a possible daughter was not true.
One source says Willliam was once married to Amy Mabry; but I don't have any marriage date. I have not seen any evidence that William was married to a Judith Martin. So I would love to see what you have on that marriage, including a marriage date.
William was born in 1742 and did not marry Nancy Mercer until 1799 at the age of 57. So it's possible that William was married twice before that.
There is one small correcton I can offer. John Richards was indeed killed in the Texan's fight for independence from Mexico. But he was not at the Alamo. He died at Goliad, three weeks after the Alamo fell. This can be confirmed online and in a book I purchased at the Alamo last year: "Heroes of the Alamo and Goliad."
I loook forward to corresponding with you and sharing what we know. There are so many William Richards in the same times and places that it's challenging to be sure we're always tracking the right one. Revolutionary War records are just one area where there is much confusion. So that's another area where I would love to know more about what you have.