I am not certain, but I believe it is from her line. My Great-Great-Great Grandmother was a Rainey, and was related somehow. I remember my Great-Grandmother telling me that her Grandmother had never told her spouse, as he was a Confederate Soldier, and hated Grant with a passion :)
My family struck her out of the family Bible because she was not only married to a Yankee but THE Yankee. :-D