Well, without knowing about your relationship we can't know what is special to you/her. edit: sorry didn't see the update. Get her a nice sketchbook and write something nice inside. maybe some charcoals too. (http://www.moleskineus.com/largesketch.html). Take a photo of the two of you and use photoshop to make an artistic image. put that on the sketchbook. for ref a quick one of me and an ex http://imgur.com/Xudad.