Boyfriend and one of his friends. Need help!

So to start off, my boyfriend is in AA and he's obviously made friends through it. There's one of his friends, who is a girl, and normally I'm fine with his girl friends, but this one has me feeling uncomfortable. I know he wouldn't cheat on me, but I feel like this girl has feelings for him because she always tries to have his attention and will sit close to him or kind of get in the middle of us if we're walking around somewhere or something. I've already brought it up to him that she makes me uncomfortable and he has reassured me that he's not attracted to her and all that, and I believe him, but I still think she has feelings for him and I don't know how to get over it and I don't want to bring it up or I'll end up looking crazy and he'll probably just think I'm being emotional or something. I have no problems with any of his other female friends, but I really don't know what to do. Just whenever he brings her up or said she was apart of something, it just gets to me really bad and I don't want to be annoying and bring it up all the time. Please help! We've been on and off a couple times for, well been together 3 years but on and off for the last 2, a couple times. I don't want to be a crazy girlfriend 😩