Due to the Aviz dynasty marriage policy, Beatrice was first cousin and sister-in-law of king Afonso V of Portugal, first cousin once removed and mother-in-law of king John II of Portugal, first cousin and mother-in-law of Ferdinand II, 3rd Duke of Braganza and mother of king Manuel I of Portugal, playing an active role in politics during the consecutive reigns of Afonso V, John II and Manuel I.

Through her sister Isabella, wife of John II of Castile, she was an aunt of Isabella I of Castile, helping to settle both the Treaty of Alcáçovas and the Treaty of Terçarias de Moura between the Kingdom of Portugal and the Kingdom of Castile, after meeting with her niece Isabella in person.

She was also predominant in the Order of Santiago, acting as tutor for her son Diogo.

She founded the Religiosas da Conceição monastery, in Beja, where her husband was buried.

In 1447, Beatrice married her cousin Infante Ferdinand (Portuguese: Fernando), 2nd Duke of Viseu, son of King Edward of Portugal (her uncle).