María de la Cerda, señora de Gibraleon

-http://fmg.ac/Projects/MedLands/CASTILE.htm#MariaAlfonsoMPedroNunez...

c) [MAR%C3%8DA Alfonso. Salazar y Castro states that Pedro Núñez de Guzmán, son of Álvaro Pérez de Guzmán, married "doña María de la Cerda"[1451]. However, in another section of his work, he says that "doña María de la Cerda Señora de Gibraleón" was the wife of Pedro´s father[1452]. Her parentage has not been ascertained. Some secondary works state that she was the illegitimate daughter of Juan Alfonso de la Cerda [Castilla] Señor de Gibraleón, and the connection with this property makes this an attractive possibility. The uncertainty about her paternity is noted by Dupont[1453].

m PEDRO Núñez de Guzmán Señor de Manzanedo, son of ÁLVARO Pérez de Guzmán & his wife [Urraca Alfonso].]