M.H.
Would they be in to Vera Bradley? There are lots of accessories for that cost, plus different patterns. What about gift cards to stores that they shop at? You could get them to two different places. If they aren't happy with them, they can switch and/or buy $10 each at both stores! What about buying them some simple make-up. You say they aren't girly, but guaranteed, they will soon want to wear at least a little bit. (Lip gloss, cool eye color, etc.) Would they like to get their nails done? Again, I know you said they aren't girly, but a lot of girls do. Do they have a movie they want? I hope this helps, and good luck!
P.S. I love the movie gift certificate idea! No child that age hates going there!