How should I reply back and reject her?

Would you want to be judged by all the things your parents do? Since you clearly are not interested in a relationship with her because of her father, then just tell her so gently. Just say something like, "I enjoyed meeting you at the party. You seemed like a cute and friendly girl, the kind of person I'd normally be interested in getting to know better. But I had your father as a professor at _______________ (name of school) and disliked him intensely. He harassed many of his students, including me. It's nothing personal against you, but I think it's just better than we not go out." She may be shocked at that view of her father or she may come back at you with something like, "Yeah, my dad is really difficult and impossible to live with. But I'm not like that at all. Will you reconsider getting together this weekend?" Then you can decide what your next step is.