Details on cutting?????????

theres this girl who goes to my school. shes in grd. 11 and its her 2nd year here(she switched to my school @ grd. 10)anyway, she sits next to me in my english and phycology cl. i think she has friends. i see her talking to kids in the hall. im not really her friend, infact, we dont even speak and we sit next to each other. i think i intimidate her b/c ive got a big group of friends and im loud and im not scared to talk back and shes the opposite.now tht i think about it i must seem like a ***** to her. i dont say hi back when she says hi to me. i look at her like shes retarted.all i do is text and pretend she doesnt exsist. the only time we really spoke was when she accedently hit her hand on my leg and said sorry i just sorta looked at her then looked away.today in 2nd period english i decided to ask her for help on a question. when i looked down at her work i noticed cuts like 5or8 cuts going across her left wrist.i sorta was in shock and decicded to sit somewhere else.i didnt tell anyone. i would never do that. in 4rth period phycology she sits next to me again. i never really went out of my way to talk to her but i know shes gone out of her way to talk to me. tomorow im gonna talk to her and try to help and well, idk even though im not really her friend and i dont talk to her it doesent mean i dont care. if she has a problem i wanna help. but she might thing im a *****. how can i earn her trust quickly and help her.