William Hardin, son of William (Indian Bill) Hardin

I descend through his daugher, Nancy Jane Hardin. I am interested in her Mother. Some say it was Mary Biddle, sister of Rachel, brother Henry's wife. Breckenridge County court records name her as Mary but I have never seen any information to support Biddle or any other name. I would like to know why she is though to be a Biddle and the names of Rachel Biddle Walker's parents and siblings. I have also seen that William Hardin had seven sons and four daughters. I know of six daughters with at least three wives: Molly Cassandra with his first wife, Cassandra, three daughters with possibly Mary including Nancy Jane, and two daughters with Caroline Innis and one son with Caroline Innis. Can anyone help?