Only reputed to be Llywelyn's daughter, but The Complete Peerage vol.V,p.373
shows no doubt. (www site : Directory of royal genealogical data). LDS file has her mother as Joan, Princess of England. Joan was daughter of John "Lackland" King of England and granddaughter of Eleanor of Aquitaine. Still there is too much uncertainty on the identity of her parents to include any (EAD)