Does you T seem open to the idea of a gift? Look around the office and try to determine if what is displayed within it might be gifts from other clients. She would probably be very appreciative but it could also make her feel uncomfortable.

I say you should still proceed though. While sticking with something meaningful, I do suggest however you stick with a single and small item. Personally I like the idea of the frame with your own artwork or a photo symbolic of how you feel.