Second, money is a problem. I can see that she is not very single-minded about you. Since she wants money, the students can't satisfy her in the end. It's better to have a long pain than a short one. Never mind what your classmates called sister-in-law. Come on, it's normal to break up in college. Just relax。 As for meeting in the same class every day, have you heard Eason Chan's Want to Cry? For the most familiar stranger, nothing happened is the cruelest revenge.
Finally, I suggest you break up, because she is not worthy of your love.