Son compartido

AITAH for telling my girlfriend that my money isn't "our money"? I've been dating my gf for over 2 years. I earn $95k working in corporate finance and she's a final year law student working part time earning around $40k I think. I'm not a baller obviously but I live with my parents and have minimal expenses, live frugally so I save a big chuck of my income. She on the other hand, is really bad with money. She doesn't piss it away on drugs or gambling and stuff but she'll buy expensive gifts for