Who married Robert Walpole (colonel)?

Colonel Robert Walpole (18 November 1650 – 18 November 1700) was an English Whig politician and militia officer who served as a member of parliament for the borough of Castle Rising from 1689 to 1700. He is best known for being the father of Robert Walpole, the first British Prime Minister. Walpole is the ancestor of all the Barons Walpole and Earls of Orford, of all creations, and of the present Marquess of Cholmondeley, owner of Houghton Hall. He is also the Guinness World Records holder for having the world's longest overdue public library book.