The Doctor, who assumed the name Kenneth for his role, had created a holodeck program to experience family life. The first program was picture perfect, and Belle was the perfect daughter. She did well in school, never disagreed with her father and always got along with her brother. The second program set up by B'Elanna Torres allowed the Doctor to experience real family life. In this version, Belle became rebellious. She had to be told to clean her room and bordered on uncontrollable.
When the doctor set limits, one of the sacrifices was Belle going to Parrises squares Tuesday, Thursday and Saturday, putting her on the second team. She protested at first, but eventually agreed. She died in an accident suffered at a Parrises squares match. The Doctor was so devastated that he ended the program. (VOY: "Real Life")