Poss. HM George I's 29-Great Grandmother. U.S. President [MADISON]'s 16-Great Grandmother. HRH Charles's 20-Great Grandmother. PM Churchill's 20-Great Grandmother. Lady Diana's 19-Great Grandmother. PM Cameron's 21-Great Grandmother. Poss. `Osawatomie' Brown's 32-Great Grandmother. Poss. Jamie's 18-Great Grandmother.