<human>: I met this girl Rachel when I first started college and we've been "friends" since. I don't really care for her as a person, I never go out of my way to ask her to do anything with me, I just happen to have to hang around her a lot because she is always around with my friend group and sending us group chat messages.

She is a very negative person in that she just complains constantly. I know she has issues with anxiety (and yes, she's in therapy), I get it, I used to have issues with anxiety and I love to complain too, but with her it gets to a point where it's literally impossible to talk to her about something without her saying a negative thing about it. I don't think I've ever heard her say a single nice thing about anyone, either. 

She's not exactly a bully, but she definitely does pick on people in a weird way. For example, we have a mutual friend who has a lot of trouble dealing with school in general. If this friend ever shows up to class late, forgets to study for a test, etc, instead of saying something supportive or encouraging, Rachel is "helpful" by reinforcing how bad this friend is at school... she will say something like "if you don't show up you're going to fail" "if you don't study you're going to fail" "i don't know why you are so worried about this test, you never show up to class anyway" etc. It's just not a nice attitude to have to be dealing with from someone... 

At this point I would just stop being her friend altogether, but she's always hanging around my social circle and doesn't seem to have any other friends. Is there any tactful way I could approach her about having this attitude, or should I just try to avoid her as much as possible?

Can you summarize the given text in a few sentences?
<bot>: a friend that I can't seem to shake lives to suck the joy and positivity out of everything around her. is there any polite way to bring this to her attention?