The website of McDowell County Oral History, which is excellent, includes local historian Anne Swan's account of Lydia, Mary, and the other children. Go here: http://mcdowellhistory.com/
and scroll down to Ms. Swan's second video.
My understanding is that Dr. J. M. Spainhour, said to be Lydia (Burchfield) Hunter's great-grandchild, is the original source of the story.
Kathy Gunter Sullivan