The 2005 obituary of her son Garrett Clifton refered to him as the son of “the late Ada Planck and Garret Bates Sr.” The obituary of her son Bobby, who died the same year, reported his parents as “the late Garrett and Ada Pettit Bates.” This presumably indicates that some time between 1982 and 2005 she married a third time to a Planck. I can’t find a death record for her under that name, though.