90% of the time, this site can be helpful and provide some much needed perspective for students who aren’t sure what to do. 99% of the advice that veteran posters give fits that description.
Then there’s the 1%. I count one overreaction and one me-first viewpoint, so we’ve all seen worse. We still shouldn’t give (nor should OP take) advice on breaking up with his girlfriend, who none of us have ever met. I don’t think much of the “It’s not your problem” mindset either.
OP: A discussion with your girlfriend is certainly in order, to make sure she isn’t choosing a school purely based off your relationship. In the long term, that is probably not the best of decisions. If Sonia Sotomayor found that her HS sweetheart wasn’t the person she wanted to spend her life with, it can happen to anyone. The odds are against a HS relationship leading to a successful marriage, and this is one time when she needs to be objective about that fact.
If she’d be happy attending UA even if you broke up tomorrow, leave the matter be. It’s not as though she’s attending Bob Jones University as an act of love (setting aside how singularly unsuited BJU would be to that purpose). This is her decision to make, and there are worse options than graduating debt-free from a state university where she can do well academically.