I'd definitely get Canvas Curse, it uses the stylus so well that it makes me people cry in the streets with joy. I know I did.
As for Nintendogs, I put off buying it. I'm sure she'd love it quite a bit, but for the average gamer it can get boring after a while. If it's for your girlfriend however, she'll probably enjoy it so it's a definite purchase for her.
And go for the DS. Although I don't recommend starting off with a game that will bust your chaps, you might want to start off light and build up to it.







