How to stop her cutting ?

Ok she's admitted she has a crush on me too but im not wanting to go out with her because she cuts. At the same time I used to cut.
Ok this is health related.

Im 15 and my crush is 14 well I met her a year ago when her friend was going out with my friend back then she was very disturbing cause she smoked and dranks and cut and od's on cough syrup.

Now a year later she dosn't drink or smoke but she still cuts and od's.
I don't know what to do I stopped cutting by venting my anger in cross country and wrestling. Well I suggested her to try cross country or some sport to vent her reason for cutting. She said no.

I want some suggestions for how to get her to stop cutting I never used any other way to try to stop so I don't know how to stop her from cutting im very confused with this and I dont want her parents involved becouse they already know and she's a good person other wise she never gets in fights or gets angry and advice?