My roommate [19F] in university faces possible expulsion for drug-related offenses. How can I [19F] defend myself from possible retaliation and threats?

Tl;dr- my roommates is in trouble with the university and is threatening my friends and I with an exposé to get us all kicked out with her.

My roommate got caught drinking with her friend in our dorm and the police had to be called because the friend got sick and had possible alcohol poisoning. She is fine now.

The police (campus police) collected evidence of what happened and a statement from my other friend T who was called in to help but didn’t drink. I wasn’t on campus the time of the incident

There is currently an investigation of the situation and my roommate and I are not on speaking terms due to this incident, her careless attitude towards it, and because she’s just an overall morally questionable person. However, she threatens to take us down with her by snitching on us for smoking weed. I smoked it twice from my friends pen and didn’t do it again because I didn’t feel good despite not inhaling it. They smoke all the time. This happens on campus and we are 19. She’s the main one who smokes out of everyone

How much legal trouble could I be in if she tells the police or university ? There is no proof

I’m in NJ