Her parents (Joy & Carl) raised Beatrice with everything she could ask for, but they never accepted her twin Ramona.They kept her upstairs in a secret room. They never introduced her to the world. Beatrice tried to play with Ramona whenever she could, whenever they let her. Her parent's didn't even give Ramona a name. So Beatrice named her Ramona. When they were about ten, their parents had a party. And in the morning when Beatrice went upstairs to play with Ramona, she was gone. Her parents had sacrifed Ramona to the Demon Paimon. However they told Beatrice that they gave Ramona away. They threatened her to never speak of Ramona again. Beatrice always felt so sorry for Ramona.
She didn't find out who her parents and their friends really were until many years later. She said that something happened to them and things didn't turn well for them. However the audience doesn't neither gets to know who Beatrice parents where nor what happened to them, since Ramona appeared and killed Beatrice, before she could say anything more.
Beatrice Benson also has an unnamed daughter. It is unknown what happened to her after Beatrice has died.