It took me pushing a shit ton of friends away and having them attack me at one of my lowest points for me to say fuck everyone this shit isn't worth it, I'm gonna work on me idgaf if anyone stays in my life or not. Personally I had a lot of abandonment issues that I hadn't worked on or even acknowledged from childhood and it subconsciously turned into a fear that everyone around me will leave me if I don't fight for them and their attention bc I'm not worth anyone's time just being me. Ok ik it sounds sad and fucked up and honestly it was, but that doesn't excuse the fact that when I got triggered I'd freak out and push people away bc I was too over emotional, and then after I pushed them away I'd either wait for them to apologize or succumb and apologize desperately myself. It took a lot of acceptance and self love to stop being a complete asswad weirdo, but yeah her issue might be that she doesn't love herself enough to feel comfortable that her friends becoming better friends with each other, prob bc in her mind it might mean that she's losing them both. Probably doesn't make sense to you, but it does to me bc I used to have this thought process all the time and I still catch myself in it sometimes. But I'm not saying this is what she's going through honestly life can go a thousand different ways and shape you in a completely different way each time, but no ones just a bitch for nothing. Something up in the noggin isn't working correctly and her thinking is probably distorted, that's all I'm FOR SURE about though. The only way you'll find out is by talking to her with an open mind, you don't need to apologize, just talk, or don't idk lol.