I can see room for improvement.
-Background creases are still showing and part of the BG are cut off
-Background exposures are off, not sure if intentional. But I'd go for something a bit darker than pure white
-The Baby looks uncomfortable laying on her front, try re-positioning her, maybe on some cushions or something.
-Boy with chinos lying down has distorted arms
-Boy with white shirt looks as if he has no legs, try and incorporate ligaments to avoid this.
-Missed focus with the boy in the orange polo. This would have been a good shot if it weren't for that
-Boy with chinos on last shot looks false smiling. Tell a joke, make a fool of yourself and get them laughing just like the kid with the orange polo.
+First shot has nice composure
+The boy with the white shirt looks like he is having a great time
+Relatively good exposure on the subjects, highlights look nearly blown on the last image however.
I would add catch lights. Kids eyes glow so well when they have a good catch light. It would make photos pop!
Also work on exposing the background, you could do this with dodging in Photoshop, were not all perfect!
Think about posing, get the kids relaxed, let them play about and snap when their not expecting it.
Also try getting some shots of them interacting with each other. It removes the tension of being in front of a camera, they will forget you were even there!
I sometimes get told I'm to harsh of a critic, but criticism makes things better.
