An engraved key chain
A picture frame with a picture of the two of you or a collage of your pictures.
A coffee mug with a picture of the two of you.
Active gifts

Tickets to her favorite show coming to town, or a concert she's dying to go to.
Treat her to dinner on top of the highest skyscraper and then go on a caleche ride (weather permitting).
Cook dinner for her, buy her massage oils, candles, and oil burners, and be at her mercy all night long.
The whole point of Valentine's Day isn't to outdo each other with gifts, nor is it to go into a store and get a gift for the sake of giving a gift. It's a time to show your significant other how much they mean to you, how important they are to you, and a little reminder in the middle of the year, amid the stress and routine of life, to stop and say, "I care for you deeply and want you to know this."

So don't get all awry about what to get her -- you know what she likes, and you know what will please her. As long as it comes from the heart, you'll be showing her that Cupid is doing his job.