Literary observations - Part 2

We have a book called  A is Adorable, based on a song of the same name. It goes through the alphabet listing positive attributes of the reader, "A, you're adorable. B, you're so beautiful." etc. etc. For J it says, "J - we're like Jack and Jill" with an accompanying picture of two children dropping a basket of apples and falling merrily down a hill. My question is, why is it good to be like Jack and Jill?! They fell down a hill and Jack broke his crown, a.k.a. his head. HE BROKE HIS HEAD! The rhyme stops in a convenient place, because had it gone on the writer would've had to find words to rhyme with "ambulance," and "severe head trauma."