My friend is cutting herself the only reason I know is because I saw her wrist and it was all cut up and I asked her if she did it to herself and she said yes but now she always says to me that she doesn't want to talk about it when I ask and I don't know what to do because she told me not to tell anyone but I really want to but I'm scared that if I do she will do something worse. Know I feel like I'm not helping her and I feel really bad.

First you are not doing this and it is not your fault. She needs to get professional help, you need to tell your parents, who will hopefully talk to her parents