A good one I recently got for my Missus (who’s into the series) is the game based upon the CSI TV show, it’s a puzzle-adventure point-&-click affair.
…Or go emu-mad with MAME and a bouquet of select girl-friendly ROMs (Rainbow Islands, Bust-A-Move/Puzzle Bobble, Bomberman World)
If she’s not into FPS but games regularly on a PC, why not buy her a nice USB pad/stick (thinking X-Arcade, but only if you intend to propose :lol: ) instead of a game: you’d be amazed the difference a good interface can make, for enjoying any game.