My daughters new bike

[deckeda]

Now that she's been on it a few times, raise the seat to where it should be, so that there's only a slight bend at the knee when the ball (not heel, not bottom) of her foot is on the down stroke. Let her know she isn't supposed to be able to actually reach the ground while sitting on the seat ... if you're stopped, you're off.

She'll object at first, until she realizes she can peddle more effectively when not all cramped up. And then she'll carry that knowledge into her adult bike riding!