YOu have a cute little kid singled out by sharp focus in this interesting image. So, by definition, you probably met the Challenge. But, of course, the voters didn't score your image very well, so I'm going to pick apart the composition a little bit, to see if I can help.
This image could be quite strong if the child was shown chasing after the ducks, or at least showing some intent to do so. Or, perhaps if the mom was down at kid level urging him on (or holding him back) .. and perhaps the other youngster in the frame could have been a bit closer to make it a really composed image. Then you could have discarded the cars in the background and concentrated on just the three major players. That could give the scene a great deal of power and interest.
I'm not really prepared to comment on how you got your blur to work since your settings information is blank. With your equipment, it should be fairly easy to ascertain these settings. It would certainly help with your next Critique if those settings were available. Anyhow, if it was mine, I'd probably have used a 300mm up to 500mm lens which would give that effect with great ease.
You're fairly new to DPChallenge with only 4 challenges under your belt, but it looks as if you're having fun and I wish you good luck in future Challenges.
I see where you were going but the blur is unnatural (the ground is in focus but the woman, closer to the boy, is not). Interesting compositionally - three is a good dynamic. Like the little boy's placement in the frame.
I am not against post-processing blurring, but if it is done in such way to make the shot unreal, it takes away from it. E.g. the sand shore behind the kid is relatively sharp and in focus, while the lady next to the kid is out of focus. Should have blurred some of that shore to the left of the kid's head. 5 for trying.
Isn't it strange that the boy is in focus as well as the shore 2-3meters behind him and the mother standing next to her son is not? Should take care of an object's distance from the camera when giving a false small-DOF feeling during PP.
Cute, but it would be nicer to only include the mother and the child in the shot, and perhaps more of the water. THe composition is just not working for me.
Your focal point seems a little over exposed, I would have tried to get a meter reading from the skin on this or change the curves of the image data in post processing to help out.
Wow, as close as the girl (mom?) is to the baby, I'm willing to bet that the blur on the girl is done via software. After all, even the ground behind the baby is in better focus.