Question: When did Blanche Of Portugal (1259–1321)'s mother die?
Sentence (from "Blanche of Portugal (1259–1321)"): Named after her great-aunt Blanche of Castile, queen of France, Blanche was the Lady of Las Huelgas, Montemor-o-Velho, Alcocer and Briviesca, the city which she founded.
Relevant evidence: No