About Malyne de Cay (De Cay De La Pole)
William was not her husband? (some records say so, some otherwise), but she did mother a child by him, Joan/Jane
William de la Pole's only known legitimate son, John, became the 2nd Duke of Suffolk in 1463. De la Pole also fathered an illegitimate daughter named Jane de la Pole, with a nun, Malyne de Cay. "The nighte before that he was yolden [yielded himself up in surrender to the Franco-Scottish forces of Joan of Arc on 12 June 1429] he laye in bed with a Nonne whom he toke oute of holy profession and defouled, whose name was Malyne de Cay, by whom he gate a daughter, now married to Stonard of Oxonfordshire". http://en.wikipedia.org/wiki/William_de_la_Pole,_1st_Duke_of_Suffolk
They had the following children:
F i Joan de la POLE was born Mar 1430 and died 28 Feb 1494.