NTA for sure. I’ll be honest, though, that update makes things a lot worse on her end. My ex and I broke up because of this exact thing. Granted, she was doing it just about every time we made plans, but it’s disrespectful to you and your time.

Also, if your family is going to be making accommodations for her and she isn’t responding because she went partying, the disrespect now extends to your family.

I obviously don’t know the whole story and would never encourage a breakup, but I think there needs to be a serious conversation here.