Advice please

Hey guys just thought I'd jump on here cause I had a question about this chick in my class. There's this girl named viola in my class and she gets top in literally everything like shes actually so smart doing work for 2 year levels above and stuff. Viola always wears long sleeves, I pulled one of her sleeves up in class and she didn't have any cuts so I think I got the wrong arm. But yeah ive seen her sleeves have cuts peeking out and heard from people that she does sh. Why though she is perfect and gets good grades too if I got those grades I'd be so happy but she just isnt. So can someone help me out here and what should I do for viola.