Here is where the pronation during the takeback takes effect.
As we can see, Rafa has a much steeper racket angle during contact than your daughter.
This allows him to generate much more topspin while still controlling his power, whereas your daughter's shots will turn out much more flat and hard to control.
As you can see, Rafa is taking advantage of his slightly closed racket face in order to pull up and across the ball at contact in order to simultaneously produce topspin and power.
This is shown by how his racket face is still in line with how it was at contact and we cannot see his stringbed.
As we can see by the racket face of your daughter post-contact, she is doing more pushing through contact rather than pulling across.
This is a result of her racket face at contact.
After adding pronation during the takeback to produce a slightly closed racket face at contact, the technique is to brush up and across the ball at contact.
So, all in all:
- Make sure to keep hands on racket longer during unit turn.
- Try fully pronating the forearm in the takeback.
- When swinging forward, try brushing up and across the ball to produce maximum topspin and power, just like Rafa.
Hope that helped!
Your daughter's strokes look great. Good luck.