The pressure can be subtle

 

The parents may claim that they are not putting pressure on her, but they may be doing it unconsciously in so many ways.

She may be putting a distance between herself and them as a way to temper the pressure.  She may also be manipulating the situation so that the parents do not get too close.

The parents should be clear in their own mind what their expectations are, rather than pretending not to pressure her.

Make it clear to her that they want the best for her, not for them, and she should make her best effort to achieve what her potential has allowed her.

They should create an atmosphere in which she feels that her effort can make a difference in how they see her, not one in which whatever she does, they still think of her as deficient.