Histogram on #1 is substantially on the left - ie underexposed. #2 is better but its always tough with black uni's especially with opposing white. For these I'd reprocess and bump the exposure up a tad for #2 and more for #1.
Suggestion: Have them mow the grass, the second picture 1/2 the ball is below the green (!!!)
Watch your background and try to get eyes. For my soccer shots that have been keepers over the spring I've been a lot more patient to get the player looking up, which I understand is hard to do with the little tykes.
For the background, I get that normally there are other games going on in the area and you have to deal with parents and teams on the bench, but if you can eliminate coach with his arms on his head (even though he's blurred out) it will take the picture up a notch.
!!!)