What if John of Gaunt, Duke of Lancaster, wife of Constans, the heir to the throne of Castile and Leon, had the following daughters?
Catherine (b. 1373-)
Mary (b. 1376-)
Joan (b. 1379-)
Margaret (b. 1382-)
Catherine (b. 1373-)
Mary (b. 1376-)
Joan (b. 1379-)
Margaret (b. 1382-)