Demon possessed?

I’m a college student, and today something really weird happened. We were doing team project, and this girl wanted to join our team, and I didn’t liked her because she was really obnoxious and had a soundcloud rapper boy friend.(who acts like a gangster) As we were trying to make a plan for the assignment, she starts to insults us for being dork or whatever, and when I suggested to use discord for communication (because rest of the teammates were in a same discord server) she said discord is for “fucking dumbasses”. She also insulted my girlfriend that she is prostitute for dating such a ugly guy. I still don’t get it she had no reasons to insult me like that, and I have never felt more anger in my life like that. I cursed at her and left the classes and got on my car. I reached for my phone and I found my rosary in the pocket. Is it possible that she could be demon possessed? Mental disorder? Idk. It was weird and scary to encounter such a fever dream of a person like this. Thanks for reading