A cute mug like this one is a great teacher gift, add in a few pieces of her favorite candy and a starbucks gift card and you've got a great gift!
A cute pair of sunglasses for her to wear during recess duty.
The thermostat in the classroom is almost always set to permafrost. A cute kimono is a really great gift. It's stylish and will keep her warm and comfy.
A cardigan is always a good idea for a teacher, especially one with pockets!
A nice supersoft Hacci (think cashmere soft) blend lounge set for weekends and those days when it has been a LONG day at school and she is ready to slip in to something cozy and relax.
And the final thing that I would recommend is a gift card. Teachers LOVE getting gift cards with a small personal note expressing your gratitude and appreciation for all that they do.