Salaam - Need advice about a college friend who smokes and drinks

Asalaamu alaikum sisters, I (16f) am in college and it honestly took me a while to make friends, but I finally have a nice group, Alhamdulillah. Most of them are Muslim except for two, but two of my Muslim friends unfortunately smoke and get high, and I’m not sure how to handle it. One friend (18f) does it, though she only does it around our circle and doesn’t broadcast it. She still prays sometimes, is active in our Muslim students’ activities, talks about wanting to do Umrah and Hajj, and seems to try to be a good Muslim - but she has this weakness like we all do. Her getting high and drinking really surprised me because she’s overall super sweet, an honor student, and a good friend. My mom doesn’t want me to be close to people like that and she tries to steer my friendships, but when she tries it hasn’t worked out - the girls she suggested would talk to boys, be rude, or just not click with me. My other Muslim friends don’t smoke or drink and are good company, so the group kind of balances out and I don’t feel pressured to join in. The friend I talk to most is someone who prays five times a day and stays away from those things. I’m conflicted. I feel bad because my mom has a fixed idea about what my friends are like and it isn’t completely true, but I enjoy being friends with them. It’s hard to find Muslim friends who don’t smoke or drink at my college, where it seems many people do. I’d really appreciate any advice on what I should do - how to keep good boundaries, stay firm in my faith, and handle my mom’s concerns without losing the friendships I value. JazakAllahu khairan.