In my experience, while your dd might struggle against slower pitching, that is nothing to worry about. In the big time games and as she continues to improve, she won't be facing those types of pitchers. I have a young lady taking hitting lessons with me who is second year 12U. She has been asked to play up for a 14U team. As with my dd, that team then jumped to 16U for a tournament. This young lady hit 3rd in the lineup and hit a couple of bombs last weekend. As I mentioned to her, for slow pitching we have strategies that can help gear down. However, if you don't have the ability to hit the heat, there aren't too many strategies that will enable her to gear up successfully.
Thanks. When they face a good pitcher who throws heat she's one of the few that had/has success. Even if they have a good change up she manages to hold back and get a piece and then revs it up to hit the fastball hard. I'm from Canada, we traveled to the States to play in an older division at Motor City Showdown. She hit great in that tournament.