Look I'm not trying to be a jerk but I never understood the concept of cutting. What do you get out of it that you feel the need to do that to yourself? It's absolutely beyond me that people get to that point, and I'm not trying to be insensitive.
Second, if you do cut and have felt the need to show your pain through scarring your own body, bringing it to school would be the last place you'd want to bring it. First of all you will be ridiculed, you will be made a target and you will be brought in front of a counselor who will call your family who will be embarrassed and not only that but they will likely make you see a therapist, which in reality if you are cutting yourself isn't a bad thing. Still though, it is social suicide. Here's something to consider: keep your dirty laundry at home. Meaning: if you have issues like you are experiencing, bring it up to family. Trust me they will give you attention, and it could be attention in a way you don't want....but attention in the way you need it.
Seriously, nobody at your school will respect you or give you the reaction that you want and quite honestly if you do show up to school like that you are an attention seeker. Trust me: cry for help to people that actually care, not the most judging group and least sympathetic group of people in the world: teenagers.
Sorry if I sound mean, but this is coming from a parent and sometimes the answer you want to hear isn't always the right answer.Edit: Kirsten's remark needs to be addressed too. You can't seriously believe that she should go to school like that in order to get help? There's better, less shock and awe type ways to get help and it is to seek someone out in private. For one, a close friend would understand and be able to help her cope better whereas if she brings it to the public in her school she will be outcasted from her friends who will be afraid to associate with this girl because the rest of the school will be cruel towards her.
I don't know if she can bring it up to her family, but it would seriously save her from bullying and all kinds of humiliation if she can handle this privately instead of making a scene at school. Her suggestion of wanting to do it alone is ridiculous and I'm sorry but she needs to understand that and not be encouraged to do it.
Everyone has scars, and showing weakness is only okay if you can trust the people around you to not take advantage of you. Wear your weakness on your sleeve and you become a target.