well for whatever reason she see's the realities of this, and it bothers her, wether she knows you or not. She does care about you as a potential friend i think so get to know her. Maybe you will get together . But you have to know that you even are compatible first. ^^ or you can just be buddies.
Still she is right smoking and drugs mess up your body and your brain.. and that doesn't heal that stays with you for life.. you should talk to people who can help you quite :] p.m me to talk more.

There is a chance that she may like you but in truth, you can't tell from the fact that she wants you to do better. Just recently I was in school with this guy and Id always bug him about smoking and even got him to quit for a while. he thought I liked him and he started liking me but in reality I felt that he could do better and he was just a nice guy that I just didn't want him poisoning his body.