Kids are really, really tough to work with it. I give people tons of credit who do it on a regular basis.
As far as general critique, the skin tones look slightly magenta on my screen. If this is a crop, I'd leave a bit more room at the top and bottom. Not only do I think that would help the composition, but if they decide to have a print framed things are really going to get tight. The crazy hair on the kid looks cute minus the strand over her eye, but the mom's hair is begging for some cloning work.
The only other thing that jumps out to me, which I'm 100% sure the client won't ever consider, is that the color, saturation, and sharpness of the leaves feel like they are competing with the real subjects. In other words, the background seems to "pop" rather than the portrait. (super nit-picking on this
) I think you could play around with it in post and end up with an even better result.