In my vast, broad, and deep experience, I have found that children, in a general sort of way, like things that are silly. It reminds me, somehow, of when I first had children and was desperately reading, I think, Touchpoints (before Aragorn, son of Arathorn, made me throw away all the child-care books in the house), and the author, talking about three-year-old girls, said something like, "Three-year-old girls can be almost unbelievably silly." He sounded…flummoxed is the best approximation. Or maybe awed.
Anyway, what I mean to say is that they are, of course, silly, and they don't really stop being silly (as far as I can tell) for a long, long time. And yet, while some books (yes, manga!) play to this, most don't, leaving the silly-seeking readers adrift, until they come ashore at Monty Python. I am here to tell you there is an excellent silly book for these readers, and you may not have considered it because it is so, so old, but here it comes, back into your conscious mind:
Image courtesy Fantastic Fiction UK.
Both girls here have loved it, but it was Chestnut who was enjoying it most recently, and it was pure happy joy. She particularly liked how often little girls pulled out guns. But most of all, it wasn't asking her to care about things she just doesn't care about yet.
You can actually read quite a lot of it on the HarperCollins website, but if you're anything like me, reading part of it will make you want to get all of it. It's just…it's just so good!