George Tolmey McMillan - Question of Parentage

I am uncertain if James (Jim) W. McMillan and Sally May Hatter (McMillan) are actually the parents of George Tolmey McMillan . The DNA of myself and of my half brother does not seem to confirm it. If anyone has information with a source / proof of who the Father and mother of George T. McMillan (born in Mesquite, TX) is I would appreciate your help in correcting these inaccuracies. Regards,
Lynna McMillan