Yes, the school garden is organic. The kids are taught to cook with the produce from the garden. They also keep hens.
The cookbook has a chapter about Permaculture, which has a chart of themes and activities: eg. under "Bugs and Other Beings of the Garden", she lists:
snail hunts
snail races
setting snail traps
pear-cherry snail investigations
insect identification
insect drawing
applying organic methods of pest management
observing the creatures
The gardening/agriculture information is fairly brief. She's a noted chef, so the emphasis is on the cooking rather than the gardening.
Alice Waters'
The Edible Schoolyard is a similar idea. I don't own her books, but I have flipped through them. They are not as glossy and child-friendly as Alexander's, which I bought for the purpose of having a attractive, child-friendly cookbook.
I think your own book is a great idea. There's a definite need and a market. Good luck with the project.