I think my friend is planning suicide?

My friend has a really hard life and has been through a lot. She has depression and is anorexic and the school knows about it and sends her to counseling. One of my other friends said she's attempted before but I don't know if it's true. So anyways, yesterday this girl told my friend she was annoying. She already hates herself as much as it is and this definitely did not make matters any better. I asked her if she was okay and she said she was fine but she always says that. She then texted me saying she wouldn't be at school tomorrow. I didn't receive the text until this morning and at first I thought she just wouldn't go because she didn't want to see the girl who said she was annoying, but now I'm worried that shes going to commit suicide. Help me please and thank you for reading this whole thing; I know it's long.

If you have a way to contact her counselor or her parents, I'd give them that information. If not, a school administrator or teacher.