Do you have her on skype? Or on facebook? You can try to talk to her on there.
What I also thought was to maybe send a letter as well? Most people appreciate a hand written letter.
I’m not really good with this subject, mainly because I didn’t really have to deal with it besides one good friend of mine. Even then I had no idea what to do.
What is really important though is to listen to them and be there for them. Self harm like many things are a habit, so maybe try and give her alternatives to cutting? I have a tag full of ideas.
One idea that I just thought of is whenever she says she has those impulses go on skype and go on camera. Get a facemask, and both of you put them on. You guys can laugh at how silly you look together, but you’ll feel better for it. You guys can even do hair masks, and figure things out on your own. Doesn’t matter if you’re a guy either because guys need pampering too :P You can do silly things like close your skype video feed, and do the no mirror makeup challenge too. Then show eachother the finished result.
Also give her crisis hotlines as well. You may not be there all the time, but she’ll be able to have access to a hotline if she needs it.
Hopefully this helps somewhat.