My great-grandparents were Amanda & Bart Pilcher. They were still living in Bolivar, Missouri when I was born in 1953, but died shortly thereafter. My grandmother was their daughter, Anna Mae (Pilcher) Kinsey. She had a sister that went by both Lizzie and Mary (I believe she preferred Mary, but her brothers & sisters always called her Lizzie). I think her name was Mary Elizabeth. She was married to an Andrew, but I don't remember his last name.
Like you, I have heard the stories of Native American blood on the Butler side of the family, but Amanda never spoke of her parents, not even to my grandmother (her daughter). I know that her father's name was James Monroe Butler, but I haven't had any luck finding anything certain about him - James Butler was a popular name!
If you would like any more information on Pilcher side of the family, let me know. I don't have a lot, but my mom does. Let me know if you find out anything about the Butlers -- we are all very curious as well.