I found an obit that gives a great lead. It is the obituary of Joseph Edgar Blackstone son of Hampton Blackstone and Annie Taylor in "The Index-Journal" of Greenwood, South Carolina dated May 4, 1959.
Joseph's five sisters are listed Mrs. Yarborough Taylor, Mrs. Britton Bryson, Mrs, Henry Parris, Mrs. Raymond McCauley and Mrs. Edward Childs.
Here is the link:
https://www.newspapers.com/clip/5784126/the_indexjournal/
