Should I tell my friend's parents...?

[xAsleepOrDeadx]

My friend has been talking about having really bad anxiety and depression. She would tweet about it, but soon delete it afterward. She would also tweet about how she sometimes feel suicidal, but says she would never do it because she is too scared to. She says it makes her feel like crap and I don't want her to hurt herself. I was going to message her mom on facebook, I prepared screenshots and a message to send. But, part of me feels like it isn't my right to tell her. But, my friend won't go to anyone for help and that she wants to wait and fix it on her own and if it gets too bad for her to handle then she will get help. But, if she is already having bad thoughts, isn't that far enough? I just really don't want her to end up hating me and not talking to me for telling. What should I do? I want to help her before it's too late but I don't want her mad at me, and she gets mad easily.