It’s their money that they put aside in case you went to college. You chose not to do that, they get to do whatever they want with the money. And instead of keeping it for themselves, they generously offered it to someone who truly needs it. Good for them.

What's wrong with that? Did you expect them to hand over the money they put aside for your college education even though you weren't going? "Mom, Dad, I'm not going to college after all, but can I have the money you saved for it, anyway? I want to take a road trip, and I've seen a really stylin' Aygo for $6500, so I'm thinking of buying it, and using the rest so I can bail myself out of jail when I try to become the first person to do meth in all 50 states." Your brother's girlfriend seems to have an idea of where she wants to go in her life, so it's up to your parents if they want to give their money to her, whether she stays with your brother, or not.

What were you expecting? To get their money that they worked for to send you to college? You decided you didn't want to go, so therefore you forfeit any right to it. I hate entitled little ***** like you. "Woe is me, my parents gave away their money to someone whose doing something with their life"