In my experience, its a very common issue with girls coming out of slow pitch. In the past she had time to wait on the ball before she decided to swing whereas now she needs to starting sooner. Bottom line here is the "swing" needs to be separated into two phases the linear and rotational. The linear phase has to be started during the delivery and it's DURING this phase that she should be recognizing if its a hittable pitch or not, and not waiting until its at the contact point. If its a strike then she is already in position to rotate and finish the swing, if its out of her zone then all she does is keep the barrel back.