Margaret’s maiden name may have been McCollough, although it is not proven yet. There were several McCullough’s living on neighboring property at that time. I have searched through wills in Abbeville County, but found no McCollough in the proper time frame that listed a daughter named Margaret McKee.
Michael and Margaret’s son, Archibald, married Martha McCullough. Could this have been his cousin?
One researcher on Ancestry.com, list Margaret’s maiden name as Housnell and that she was born in England. Again, no proof or evidence were provided. I’ll stick with “family lore” that she was a McCullough until I see evidence one way or another.