HM George I's 8-Great Grandmother. U.S. President [B, HARRISON]'s 11-Great Grandmother. PM Churchill's 15-Great Grandmother. Lady Diana's 17-Great Grandmother. PM Cameron's 17-Great Grandmother. HRH Albert II's 17-Great Grandmother. Louis XVII's 12-Great Grandmother. HM Umberto II's 16-Great Grandmother. Gen. Pierpont Hamilton's 16-Great Grandmother. Poss. Jamie's 17-Great Grandmother.