Children on drugs

Well I'm a teenager and I happen to have a friend who is a few years younger then me. She's 12. She told me today that she was scared because she had did meth and hasn't slept in 5 days. I'm really worried about her, and I don't know what to do. I feel like I should tell the school. She said her parents know but she didn't say what they did.. Can anyone give me advice on what to do?