I don't know if I would recommend picking up her foot up entirely, but pivoting onto the tip of her toe during follow through is fine.
I do not think that trying to pivot to the tip of the toe during the follow through is a good idea!!! This will promote drift to the front side and also promotes coming up off the lower half. The natural lift off of the back foot should happen due to the proper sequence of energy releasing through the swing. It should only happen for a split second when the barrel is flying through the hitting zone.
Don't force this natural action, it is a byproduct of a good sequence!!!