I know that it's "the thought that counts" but whatever you get, please attach a gift receipt. Target gives them out easily at the checkout line, as does ToysRUs.
A 10 year old girl might not like electronics or the latest fad things (I know mine doesn't), especially if this is the only gift she'll be receiving. A $20 giftcard to Target with a small (under $3) Holiday candy or craft or cute socks (with the gc inside) would tickle pink many a 10-year old girl.