Wife of William Isham. Mother of Henry Isham. Ancestor of Thomas Jefferson American President. Daughter of William Brett, Esq. of Hearne (in Toddington),Bedfordshire & wife Mary.
Believed by the Rev. Frederick Brown, M.A., F.S.A., to be descended from the Brett family of White Staunton (a pedigree of which appears in the 1568 'Visitation of London'), Mary & her brother Edward were the children of William Brett of Toddington, Bedfordshire and his wife, Mary Toddington, of the same."
Sir Edward's will was proved 17 Mar 1683. Having no children and his wife predeceasing him, he left a bequest of 20/ to his church, and in a codicil also left bequests to the descendants his sister Mary Brett(1604-1682), wife of William Isham (1587-1627). Most notably, to the two surviving offspring of Mary and William's deceased son Henry Isham, Sr. who had removed to the Virginia Colony and there married Katherine Banks, widow of Joseph Royall. The two living children of Henry & Katherine who inherited were Anne (wife of Frances Eppes) and Mary (wife of William Randolph 'the immigrant')". Through these two female descendants, Sir Edward Brett and his sister Mary are related to some of the most influential founding families in America: Byrd, Carter, Harrison, Lee, Nelson, Page, Washington, and Jefferson.