Well, i m not going to tell you that its not your fault or something.
Attention seeking or any other kind of tricks a 12-year-old can play...Maybe she is just thinking SI is cool or something like that.
After all,something must be done to her. Will you talk to her about it? Can you handle it? Or perhaps your mum would be a better talker? Since the worst has not happened, we gotta do something.
take care