All I have is an 11-1/2 year old, but here is what she is getting - maybe it will spark at least an idea?
Cell phone - finally she won't be the "ONLY kid in 6th grade without one!" That battle cry never swayed me, though, she's only getting one because there is an actual need for it now. And she's only getting a prepaid with a certain number of minutes for the whole year - if she goes through them in less than 12 months, then she gets to pay for the reload!
Foot Spa and a Mani/Pedi gift basket that includes all sorts of nailpolish, foot lotions, nail files, etc.
Sound machine (one of those machines that make rainforest sounds, etc. for sleeping)
Paints, canvas, brushes, brush cleaner - she's an artist, took 2nd place in the CA State Fair for her age group this year with her first oil painting ever

Christmas is a great time to stock her up on supplies.
New robe and slippers
Curling iron
Subscription to Teen Vogue (from mycokerewards - I like free!

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Rip stick
Lots of jewelry - costume rings, bracelets, a few necklaces. I've been picking it up at different clearance sales throughout the year. It will probably all go into her stocking, but might make it into a few boxes under the tree
A new tote bag filled with travel-related supplies for our trip to China next summer (Panda Pee Wee pillow pet, guide book on Beijing, passport cover, custom luggage tags I made on Artscow.com, travel journal and pen, sketch pad)
Other things i know she also wants are a pair of Toms and a lighted makeup mirror, but I am leaving those for family to get her if they want.