What about this book?
The sum of my life.
Wu mei has a new mother and she is very mean. With the new mother she gets all new sisters. Since Niang is the wife and has children they get to be on the first floor while Wu mei and her 3 sisters and to 2 brothers sleep upstairs. Wu mei is going to school and have an election for class president and Wu mei won. Her friends have a celebration at her house without her knowing which was a big mistake.
Niang never lets wu mei have a party or let her go to one. Wu mei tried to tell them to leave but they made so much noise that Niang called Wu mei and asked what is going on. She told her that her friends were over here throwing her a party that she didn't know about. As soon as Niang heard that she started yelling, the door wasn't even closed so everybody downstairs could hear. Wu mei over heard her parents talking about sending her away at an orphanage.
So they did but it was actually a boarding school. She watches as her parents leave and led to her room which she shares with a bunch of students. There are curtains in the room beside each bed to give privacy. Some of the kids started to leave because a war that was starting up was not to far away. Wu mei was the only one left and picked up by Niang's sister.
She was taken to her fathers new home. But soon she was dropped off at a new boarding school and left there with the other kids. After she has been there a while her aunt Baba the one she used to share and live with sent her a letter. What the end of the letter said was "my Chinese Cinderella".