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.
Princess Sophie of the Netherlands Princess Sophie of the Netherlands (Wilhelmine Marie Sophie Louise; 8 April 1824 – 23 March 1897) was the only daughter and last surviving child of King William II of the Netherlands and of his wife Grand Duchess Anna Pavlovna of Russia. She was heir presumptive to her niece, Queen Wilhelmina of the Netherlands, for seven years, from the death of her brother until her own death.