A new game just came out called EA Playground. Seems like a good gf/bf type game. Google it and check it out.
Maybe a fighter game like Naruto:Clash of Ninja Revolution which also just came out. It's the best fighting game for wii, except Guilty Gear X2, but she probably would like Naruto better, and it has simple controls. Unless she's one of those rocker, slightly gothic, anime lovers..