Margaret would be the last princess born to a reigning English monarch until the birth of  who's wife?
Elizabeth of York Elizabeth of York (11 February 1466 – 11 February 1503) was queen consort of England from 1486 until her death. As the wife of Henry VII, she was the first Tudor queen. She was the daughter of Edward IV and niece of Richard III, and she married the king following Henry's victory at the Battle of Bosworth which started the last phase of the Wars of the Roses. She was the mother of King Henry VIII. Therefore, she was the daughter, sister, niece, wife, mother, and grandmother of successive kings and queens of England.
Joan Bulmer Joan Bulmer (1519–December 1590), born Joan Acworth, was an English gentlewoman during the reign of Henry VIII. The daughter of George Acworth and Margaret Wilberforce, Joan married William Bulmer at a young age. The marriage was short lived, however, as she left his house to enter into the service of Agnes Tinley, the Dowager Duchess of Norfolk. While in service to the duchess Bulmer became acquainted with Catherine Howard, who would go on to become the fifth wife of King Henry VIII. It was during this time that Joan became involved in an affair with Edward Waldegrave.