Nice detail on the face. Your levels look a tad yellow and your light is a touch harsh in that the ball is blown out on the left and the top. Perhaps play with the contrast and bright just a tad? Nice stop action and yet it still shows movement in the hand and foot. Oh, the concentration!
This is a big victory? I know nothing about this kid and without any background info this just looks like a kid kicking a ball. That's about as triumphant as a kid falling asleep.
I love the expression on her face (the tongue is a classic). I think the motion works - a faster shutter would have stopped the motion and taken away from the theme. Getting "Triumph" from this is just a bit of a stretch for me.