Clicking on the top header redirects back, but if I hadn't read your post I wouldn't have known that. Consider adding a "Home" button to the menu.
As a matter of personal taste, the bright colors hurt my eyes and I wanted to leave the website quickly. I realize that it is a children's site and it is good to create a fun theme, but I think mostly adults will be visiting it. At the least try using a black font with the light green headers. The white font is hard to see.
I am not much good at spelling or grammar, so I can't say much there. All in all it looks great.