she definitely knows, but she probably also knows that if she was the one to confess first he would just think she was making fun of him/would spend all his energy thinking he's not good enough, so shes waiting and trying to build up his confidence and make himself feel desirable.
and i mean if you were her, why would you mind the wait? you already get to go on dates and spend all your time with the boy you like, making memories together and stuff.