Lovely work on this piece, I can tell you put a lot into it. c:
The characters are all very carefully outlined and coloured -- in fact a lot of your work is super clean and refined. Looks good!
I like that your background doesn't take much attention away from the characters even though you've made it so detailed. With such saturated colours in the tree bark and leaves, it's good that the foreground is a lot more neutral. You also have a good grasp of depth when it comes to multiple character illustration, too. They don't appear to be on the same plane-- they're clearly three dimensional, which a lot of artists struggle with.
My one observation (if I absolutely had to find something to nit-pick) is the mom's hat blending in with the background a bit much. The rest of the characters stick out because they're drawn with brighter colours over-top of less intense backgrounds, but the hues in the mother's hat match the tree bark almost perfectly, so she blends in a bit much. I'm probably not saying what I mean well enough, but an easy fix would be to lighten up the tree-bark with less deep colours or more leaves so that the mother is more defined.
Haha sorry, I'm rambling.
All in all, this is a really nice piece and I hope my review was somewhat useful!