They are all very nice, and any knit picking here is just that:
1: Too contrasty. You have blown hilights and plugged shadows. I am not crazy about the framing, and I wish I could see more of the pen to get an idea of what the child id doing. Excellent capture of that peaceful intent play you get at this age, and seem to loose in a couple years.
2: I really don't like the blown hilights in this one, but DOF is great. It appears that the hot hilights were created in post, which makes the transition from the child's profile to the background harsh and uninviting.
3: Shadows very plugged up, to the point that the neck and chin blend into the torso. I am very much not a fan of the background here; seems "boxed in" rather than framed. Blown hilights in the arm and hair, but not terrible. If data is present, perhaps mask in the hilights in the wrist area.