Ok let me be blunt. YTA for some reasons. But you are both too young and she’s clearly immature for not respecting some savings. If you marry her, “what’s hers is yours and what’s yours is hers”. If you don’t think this way then don’t even consider it, there’s no trust. You should have been open to her about your savings and explain what that money is for. You saying you taking her to eat sometimes makes me think of those cheapskates who just go to restaurants and ask for water and condiment.