Edward
Edward is an intelligent man and he had a good education and he has a good level of culture. So Edward is a proportional person, instead he can to have personal thoughts and he can to conciliate his love for Florence and his physical desire during their engangement.

Florence
Florence's relation between mind, brain and body is more complex. Her mind creates a barrier to her physycal desire, probably it creates this barrier for the trauma in her childhood.
She finds a space for her personality, when she plays the violin only and she is able to organise togehter her mind, her brain and her body.