Here is my list of games she may enjoy.
LittleBIGPlanet
PixelJunk Monsters
Uncharted
Buzz: Quiz TV
Although this may not work I found it to be flawless in my attempt to get my girlfriend into some more serious gaming, plus it is cheap.
Final Fantasy IX
My girlfriend couldn't but get enough of the Zidane/Dagger love story there. She even got upset during the ending, I made her think Zidane died. 
She may even like Disgaea for the humor. My girlfriend was iffy about that game, she said she didn't care for strategy games. I opened up Youtube, turned on a couple of Disgaea episodes, she found it to be funny as hell and she instantly fell in love with the characters.
She then breezed through Disgaea 1, Disgaea 2 and then Disgaea 3, all within a matter of 1-month.
iPhone = Great gaming device. Don't agree? Who cares, because you're wrong.
Currently playing:
Final Fantasy VI (iOS), Final Fantasy: Record Keeper (iOS) & Dragon Quest V (iOS)
