MetaFilter has a nice thread about kids books by people you might not have expected to write kids books. Many of them have been mentioned on DT before: Gertrude Stein [twice, kind of]; bell hooks; Graham Greene; and Sylvia Plath, of course.
And there's a whole blog about such books, We, Too, Were Children, Mr. Barrie, which is very handy and attractive. I will be raiding it shortly.
Meanwhile, there is much you should check out and comment upon.
We, Too, Were Children, Mr. Barrie, by Ariel S. Winter [wetoowerechildren]
"Once upon a time there was an elephant who did nothing all day." - E. E. Cummings [metafilter]