Deep down, you may regard her as your opponent. She is better in some ways. You want to surpass her. Maybe you are a little envious of her (pure speculation). ........
These thoughts are normal.
It's normal to have such a dream, so don't care too much.
The reason for dreaming may be the pressure of life and study or the posture of eating, drinking and sleeping before going to bed. Just pay a little attention to these aspects.
Have a nice day!