HM George I's 19-Great Grandmother. HRE Ferdinand I's 16-Great Grandmother. U.S. President [WASHINGTON]'s 20-Great Grandmother. PM Churchill's 24-Great Grandmother. HM Margrethe II's 26-Great Grandmother. Gen. Pierpont Hamilton's 25-Great Grandmother. Poss. Agnes Harris's 16-Great Grandmother. `Osawatomie' Brown's 26-Great Grandmother.