One thing I like to do before I use USM, especially wth lots of tiny details (like leaves, branches, grass) that are not part of the subject, is this: Mask around the subject so that the main thing that gets sharpened is the subject. That way the uninteresting details don't get sharpened. I think this image could benefit from that. It appears that USM oversharpened the grass. The girls is PERFECT however! Good luck in the challenge!
This is a very sweet photo. The young girl appears to be totally engrossed in what she's doing rather than trying to pose for the camera. Two areas in which I see room for improvement: there appears to be a green cast to the color, and cropping it a little closer on the right. The cropping is just a matter of taste, but I definitely would have scored it higher if the colors had been better adjusted.
This is a really cute photo. It looks like you brightened the whole photo a lot in order to show the girl better, but that has left the background a bit too bright. Still, nice shot of a very cute girl. :-)