Sure! This isn’t supposed to be a manga club. The problem is that what we associate as children books in the West, 日本人 associate with manga. That’s also why it’s important that everyone shares any extra book suggestions they might have 
From what I researched on google/forums, amazon.jp seems to be the place to go to order books in Japanese. That’s why I linked only from Amazon in the suggestions that I gave. Not sure if there’s better places out there though.