Howard has hit a big concept right on the head. I have stressed to my girls for years that Hitting is like dancing. It is all rythm and timing. Most girls have this rythm down and when they hit on a pitching machine, they perfect that timing. In their head they can go though each step 1, 2, 3...
Live pitching changes that, but it doesn't have to. There is not set standard or way and every girl does things a bit different, but a simple concept is the three Rs. Ready, Recognize, React. When young girls see live pitching they wait too long to get Ready. Thus, the rest of the steps are late. Getting to the ready state is the key. Then we only have to recognize and react, essentially cutting the actions down 33% (only 2 of the 3 Rs remain). The ready part has to be done earlier, like Howard was saying...during the pitchers movements. I preach the short front toe tap, not a big step or high leg kick, like Howard described. Once she is really "ready" the rest will come, just like off the pitching machine. I would focus on the drills that will help her learn when to be ready faster. In my opinion, even being to early is better than being to late.