If you come up with nothing better than gift cards, buy like 5 of them for different places and make her go on a scavenger hunt for them. Have a nice note with each one giving her the clue to the next one. Have a coupon for "Driving you to all these stores and carrying all your purchases, and no complaints at all" with the last gift card.

Hell, that seems like a good idea. I might do that.h: