I second the above poster--6pm.com carries a select line of UGG boots in youth sizes at a discount. My DD11 has been asking for a pair since Christmas of last year and I couldn't see paying that much for boots when her sizes are changing by the month. However, I did purchase a pair of Classic Tall boots in Chestnut Fireworks for 1/2 price. They are a little roomy to allow for some growth and she is thrilled with them.
Good luck!