I'm not sure if you've heard of these guys, but if not, look for "Piano Guys" on Youtube. They have a lot of stuff there, some more/less appropriate to a pianist playing solo. If you find anything you like, they have links to where you can buy the sheet music.
I've been listening to them a lot lately, as DD9 now requires them to get through her ridiculous volume of low-value test-prep homework lately, and I think they make a lot of music that's a fair match for how you describe your DD's style.
Hmmm... Simple Gifts is nice enough, I suppose, but it needs some Disney and Jason Mraz to really make it go.
There's one called "All of Me" where a forearm smash is a legitimate piano technique, not a pro wrestling technique, and surprisingly doesn't sound at all like the wrestling move would feel.
Hat tip to aquinas, who turned me on to them to begin with.
