She married Sir William Gascoigne, "the Younger", son of Sir William Gascoigne and wife. Lady Margaret Percy was a descendant of Edward III. She married Sir William Gascoigne V (c 1450 – 1486), son of Sir William Gascoigne IV (c 1427 – c 1463) and Joan Neville (c 1436–1464) (great-granddaughter of Robert Ferrers, 5th Baron Boteler of Wem and Joan Beaufort).
Their daughter Agnes (or Anne) Gascoigne married Sir Thomas Fairfax (died 1520–1521), who was an ancestor of Catherine, Duchess of Cambridge. The couple had the following children:
Sir William Gascoigne VI: married firstly Alice Frognall and secondly Margaret Nevill (daughter of Richard Nevill, 2nd Baron Latimer of Snape). Had issue by both marriages.
Second son by first marriage, Sir Henry Gascoigne, was ancestor of the Wyvill Baronets (from the 3rd onwards).
Margaret or Margery (c 1473 – 1515): married Ralph Ogle, 3rd Baron Ogle, and had issue. Anne or Agnes (c 1474 – 1504): married firstly Sir Thomas Fairfax (c 1475 – 1520).
She had twin sons: the elder, Nicholas, was ancestor of Diana, Princess of Wales and the younger, William, was an ancestor of Catherine, Duchess of Cambridge (see here for descent chart). Married secondly Ralph Nevill, of Thornton Bridge.
Dorothy (c 1475 – 1527): married Sir Ninian Markenfield (died 1527).
Ancestors of William Howard Taft, 27th president of the United States of America Sir Ninian"s other wife was Eleanor Clifford, daughter of Henry Clifford, 10th Baron de Clifford. (Of interest: Sir Ninian"s sister Anne was ancestress of George Gascoigne, poet, and Zachary Taylor, 12th president of the United States of America).
