I would move the one with the "red riding hood" girl with the mice & acorns up to the top next to the pictures with the moles, since they are more similar in style, and it transitions better to the images with humans.
I like the 2nd row as-is, since they have a similar feel & style.
I think the giraffe one would be better grouped with the tiger & poodle images.
I would cut out the mouse flying on the leaf, since it lacks an interesting composition. And maybe the Alice in Wonderland..
I'd also prefer to the see spot images (white backgrounds) grouped together, & the full page images grouped together. So I would put the Kangaroo kid next to the girl with the duck.
It would be nice to have a 3rd wombat illustration. (I don't know whether that's good practices or recommended or not, but it just seems pleasing to me, especially since your layout would fit a row of three images.) But if you don't have a 3rd wombat, I would put the dog with the cookies on that row, after the wombats.
The two with the wombat character are my favorite of all the illustrations. It's really cute.