Girl stole my phone at school? Should i say something if i see her?

[Caligula]

If I were you, I'd go to the office and file a complaint. Ask them to call her in and then to dial your number while she's in the office. If she has the phone on her and it's on, it will ring.

However, you don't actually have conclusive proof. If the phone is off or if she's put it somewhere else, the office isn't likely to be able to do much unless she confesses.

If you try stealing her purse, on the other hand, you can end up in jail. "I think she took my phone" is not a defense to theft. Even "I know she took my phone" is not a defense to theft, and you don't really know, because it's possible someone else came in, found and took your phone, and left the bathroom before you got back.