Beatrice of Provence sibling Margaret of Provence
Queen of Sicily
Beatrice's sister Margaret, the new Queen of France, publicly offended her in 1259, by not seating her at the family table; she claimed because Beatrice was not a queen like her sisters, she could not sit with them. Margaret had hoped to provoke her sister in treacherous behaviour so she would have a valid reason to invade Provence. Beatrice "with great grief", went to Charles and he reportedly told her:
brother or sister kin