Most Helpful Girl
She probably cheated on you and now she feels bad and says that you are too nice for her, my advice: Make her soooo jelous till she regrets but don't be a bad boy just to impress her, believe me it won't work and worth.
Most Helpful Guy
Either she is sugar coating something or she feels like her parents would have a very lowly opinion of her. She may have also been seeing someone else while seeing you and simply be choosing him over you. You never know. Don't put too much thought into it. It just seems like she was giving you a "nice" rejection to avoid some confrontation.