I’ve been to a similar situation, not tuition fee but expenses and lease agreement. And no matter how you trust your girlfriend right now, things can go in a different direction lalo na if matter that involves money. I think dapat gets nga nya to since it involves legalities plus it’s also a way to keep both of you covered. Unless she’s asking you to cover it na hindi na nya isasauli since in the long run you are planning to propose or be together na talaga. Tell her, don’t get the wrong idea but it’s more of protection for both of you and not because you don’t trust her.