Margaret would be the last princess born to a reigning English monarch until the birth of  who's wife?
Margaret, Countess of Pembroke Margaret of England (20 July 1346 – October/December 1361) was a royal princess born in Windsor, the daughter of King Edward III of England and his consort, Philippa of Hainault. Margaret would be the last princess born to a reigning English monarch for over a century, until the birth of Elizabeth of York in 1466. She was also known as Margaret of Windsor.
Margaret of Bourbon (1438–1483) Margaret of Bourbon (5 February 1438 – 24 April 1483) was the daughter of Charles I, Duke of Bourbon (1401–1456) and Agnes of Burgundy (1407–1476).