My mom goes in my room while I’m gone and won’t stop

I (14F) have a mom who goes into my room while I’m at school or not in the house, and moves my stuff around without my permission. She also lets my siblings go into my room while I’m gone even though they both have their own rooms. I’ve tried to get them to stop, but my mom gets upset with me when I do, telling me its okay for them to go into my room. I’ve also considered locking it when I’m gone, but she won’t tell me where the keys are. What can I do about this?