Cuts :(

theres some girl in my class i really don't know her but i think shes cutting i don't know for sure but i saw red lines that must have been cuts but i can't see anymore she always wears a wrist thing i would tell my teacher or someone but i figure they'd freak out and if i was just imagining it i'd be really stupid
What should i do i don't want her hurting herself but i have no idea ?

well it's really considerate and nice of u to care so mucha bout a person u don't know
but i used to cut myself and i still have scars and i have to hide them from people cause if anyone finds out i'll get in unbelievable trouble.... so don't tell anyone right now but talk to the girl and find out if they really are cuts and try to help her nad if u see that it's gettin serious then u can get help

You could tell an adult or a counselor.
that way, they can take care of it for you.