Like its predecessor,
The Neddiad, whether or not your kids will like this depends entirely on their particular senses of humor. Unlike humorous fantasies from, say, Douglas Adams or Terry Pratchett, the story won't carry readers through this if they don't get the jokes: there isn't much plot, and what there is doesn't make a whole lot of sense. Author Daniel Pinkwater isn't interested in any character development either -- Iggy and her friends are more or less just oddball blanks to whom odd things happen.
So then, the humor, upon which enjoyment of this hangs. It's not broad, or potty, or slapstick, or humiliation humor -- it's gentle humor, of the polite sort, the jokes of a kind grandfather with a twinkle in his eye. Some of it is wordplay, some arch references, and a lot of the author amusing himself and if you want to go along, fine, he's not bothered either way. From the Book below has a sample, and if your kids find it funny, then they'll probably like this book. If not, you might want to look for something with a little more story and character -- just in case they don't get the jokes.
From the Book:"We're going with you," Neddie Wentworthstein said.
"To the hootenanny in not-in-New-Jersey Old New Hackensack?" I asked.
"Yes, the hootenanny, or hauntenanny, or walpurgisenanny, or whatever it is. If you're going, we want to go too," Seamus Finn said.
We were sitting on the secret closet stairs to nowhere, drinking Dr. Pedwee's cream soda and sharing a bag of Gypsy Boots's whole-grain cuchifritos.