Friend in extreme danger?

my friend sneaks out every night and walks around her neighbor hood in skimpy clothing she doesnt mean to ( the clothes part i mean) but it always turns out like that. i worry that something bad will happen to her. i told her this and she just laughed said that nothing would happen but she doesnt live in the best part of town and she is extremely appealing which probably doesnt help the issue. I dont know what to do. i even tried to tell my mom and she didnt do anything. my friend and i are only 12 please help!