You can always make your own! Lots of great DIY hacks online.  Your best bet is to get to know the teacher and gift her some fun oily things – a nice bottle of premade Thieves cleaner for her classroom (and one for her home ha), a Thieves bottle to replenish with, some oil samples to include in the sprayers.  That way the teacher is more likely to actually use the products in the classroom where your child will be!