Um..... You ether have to ASK her (she has to like you), Or you just go down stairs and hide in her Bag by the front door as I recall.
Ive tried asking her to take me back, she just keeps gettung angry everytime, every part of the day, from morning to night.
In the evening you can ask her to let you out of the cage. If you go down to the first floor you can find her shoes there and hitch a ride in them back to the school.
thank you