Jesus there's something wrong with you people.
If you managed to get her to a lan or smuggle a second compy into the house, NWN is golden.
Katamari Damacy, addictive and fun for the whole family. Beautiful Katamari is the 360/PS3 version.
Easing her into FPSs takes time and dedication. I am lame as hell at FPSs but since my husband will sit down and pay attentiont o me, I'm pretty easily talked into a few rounds of coop Halo or RE5, but keep the difficulty down, don't get anything that you can die really easily in, and for the love of god, let her do better than you.
Bioshock isn't multiplayer but leave it lying around or let her watch you play to get her a little intrigued with non-maxis creations.
The key here is compromise. I didn't know how much fun it was to pwn my husband at Halo (I am epic with a grenade launcher as it turns out), until he made the deal that if he created some sims on my game and helped me pass a Katamari level, I'd have to play some shootemups with him.
And let her have the shotgun in RE5