The lever in Abbie's room shouldn't be there, it's a bug, and it's been removed in the newest version. To get Malia out of her room, talk to her mother downstairs and have food with the family, then Malia will be doing her chores downstairs.
When I talk to the mother she says dinner is not ready yet and I can talk to girls upstairs. Talking to them does nothing; talking to Abbie just says all her parts are complete and there will be more in future updates. I see no way to get dinner to start.
