(First off, does she have a counselor or mental health professional to talk to? Even some hotlines to call? If not, maybe gently suggest some of these options for her.)
I think the most crucial thing to do in this situation right away is to tell your friend that you love her. Maybe you think this might not make even a small difference because you are not one of her parents or guardians or immediate relatives, but letting someone who is in such great pain know that they are loved can actually be incredibly healing. It may only be a temporary healing, but that is better than no healing at all.
And honestly, telling her not to self-harm is not going to solve the problem or even begin to solve it. Telling her that you wish she wouldn’t hurt herself- instead of outright demanding that she stop this habit that is familiar to her and difficult to drop- is more beneficial. That way she knows you care and hope that she won’t continue to cause harm to her body, but also knows that you are not someone who is going to boss her around, tell her what to do, or ignore her side of the story. That can help develop more trust between you two.
Also, tell her the way she’s feeling won’t last forever. It will not always hurt like this. Tell her that. Even use some of your own examples- do not tell her that you “understand exactly what she is going through.” Instead give her an example of a time when you felt pain or you felt bad and thought it would never end, but how it eventually did. Make sure you let her know that her pain is only temporary, even though it may feel so heavy.
Giving her a list of reasons to live or a list of alternatives to self-harm is also a good option- or even a list of resources she can go to, whether they are crisis hotlines, counselors, even support networks online. That way she has immediate options to go to when feeling so bad that she wants to hurt herself.
Sending her some sort of care package or “survival package” for the times when she’s feeling the worst is also another idea. So even though she’s 10 thousand miles away, she still has a piece of you with her. It could be full of things to distract her from thoughts of self-harm, and things that comfort her, like candles, lotion, her favorite book, handwritten notes or poems, trinkets, jewelry, coupons for ice cream, photos of cute puppies, inspirational quotes, you name it.
And lastly- tell her what you just told me. That you don’t want to lose her, and she is valuable, and no one else wants to lose her either.
Give her love, as much love as you can. Just do your best. And never blame yourself for whatever happens next.
P.S. This poem might help, if you’d like to send it to her.
Let her know that every day is a fresh start. That skin heals below the surface before the top, so while the damage may be visible the next day, her body has done more than she realizes to help her move on. Let her know that I, and every other person that reads your ask , reblog or no, has her in our thoughts.
And anon should know that they’ve helped more than their friend. When people with vices see others trying to support those they care about, we remember all the work that our own loved ones committed to us. Whether it was ten days, ten months, or ten years ago, everyone is at risk of relapse. Everyone needs to see that their self-harm will never not hurt anyone but themselves.