Valentines for someone already in a relationship...?

long story short, I like her, she likes me, things are too complicated to ever have something serious, but we hang out all the time and have a unusually special connection. Nothing has happened, yet.. She is in a relationship, but not 100% happy, but has reason to not just pick up and leave.. She is ignored, and while I dont think it would be appropriate to buy her something, I want to show her that there is someone that thinks she deserves to be thought about and cared about for her. any suggestions?? being discreet is a must and I dont want to have that "I love you" message, just I think you are a an amazing person message...