Suicide. Cutting. HELP!!! (UPDATED)

My bestest friend in the whole world texted me tonight. She said that she got into another fight with her parents. Her parents are really controlling and are just tbh evil. They put way to much pressure on her and it is tearing her apart. A little while into the conversation after we'd tlaked about why they were fighting, she sent me this.(this is the whole convo so far)

I'm specifically talking about the cutting and suicide. I litterally started crying when I got this text. I only want whats best for her. She is so smart, she works so hard, and tries her very best to be everything her parents want but they just expect so much out of her.

Ive seen this coming for a while but this time it is, you know, real.

I have her Moms contact info and I'm going to have a sleepover with her tomorrow night. Her parents need to know about it. The tension is just so high between them(I can feel it when I walk into their house) I don't think they could sit down and have a decent conversation, without it ending in a fight. I am seriously considering telling her Mom/Parents for her(it'd be easier almost like sending a letter). Of course I'd ask my friend before hand, kind of plan it out, but is it the right thing to do? Is it appropriate?

I've wanted to say something to her parents about how they treat her but my friend always tells me not to. What should I do? She clearly needs help and I only want the best for her. She doesn't trust many people and I think I'm the only one she trusts with her feelings.

But also, what if she isn't planning on telling her parents?(we all know how badly that could end) What if she isn't willing to accept help? What if she won't do it herself and tells me not to?

I mean her parents wouldn't really be mad at her for having depression, would they?

Then comes the question, if they were told, would they be willing to get her some proffesional help?

I seriously don't know what to do here. She is really shy and dosent like to talk about her feelings. She's also really afraid of her parents being dissapointed or judging her for doing something wrong or showing any weakness. I seriously think that she won't tell them if left to do it on her own. HELP!!

(I also posted this in another board but got no responses)

UPDATE:

So they know now. She wasn't going to tell them but because of how controlling and obsessive they are, they found out themselves. I don't know how they reacted, what they are going to do, if they are finding her help or anything. I should find out tomorrow when we talk about this. I might post another update in a few days.