First off, iPods are out of the question anyway! That's the first thing people jump to with teens but did they ever stop and think that most people on the angel tree don't have one?
Anyway, thanks so much for your help! Even if you can only afford $10, whatever you can do helps. If possible, find some friends to contribute though so you can give her a LITTLE more.
Aeropostale is having a 50% off sale. There are some cute necklaces that are $6. My daughter came home with some. Check that out.
Make-up is another good idea. A thing of mascera, eyeliner, blush, lip gloss, cover-up and possibly eyeshadow? Plus a small little travel case. That's probably closer to $20 though.
Another thought is a set of hats, gloves, and scarf. Target has them for $5 for a set of all 3 (if I remember right).
Again, anything you can give will be appericated.
EDIT: If you want to go down the book route, the Clique or Twilight series is a popular these days.