From the dad of a 16 year pitcher, I would have to say that everyone here is giving some great advice and I am sure they are all correct. The only thing I will add is to be straightforward with your daughter and ask her why she does it different in games. You may be surprised by what she tells you. It could be that she is afraid of being hit with a line drive, she may be afraid of not pitching strikes. It could be many things, but I will agree with TheBearMay, that for some reason she is trying to place her pitches and thinking too much. Basically she is trying too hard instead of trusting her arm and hand to do what it does in practice. With a batter standing there it makes it much different than practice but with your help continue to build her confidence in her ability and to just trust her arm. Once she honestly sees and experiences the results, she will understand it is more of a feel than trying to memorize or think each movement. It should all be from muscle memory and habit. Hope this helps. And the best of luck to you and her.
Sincerely,
Ed