I dont know how to sort it out?

I am getting worried about my friend, she is doing loads of different things with boys and smoking and drinking and she is only 13 and i dont want her getting in to trouble, what am i meant to doo, i have tried to talk to her about it but she just clams up, i am worried she is getting depressed should i speek to my pastorol care teacher at school about it or not ??