wonder child vs kid

wonder child and kid both are nouns.

Word	Noun	Adjective	Verb	Adverb
wonder child	Yes	No	No	No
kid	Yes	No	Yes	No

As nouns, kid is a hypernym of wonder child; that is, kid is a word with a broader meaning than wonder child:

Other hypernyms of wonder child include child, fry, minor, nestling, nipper, shaver, small fry, tiddler, tike, tyke, youngster, prodigy.

wonder child (noun)	kid (noun)
a prodigy whose talents are recognized at an early age	young goat
	a young person of either sex
	a human offspring (son or daughter) of any age
	soft smooth leather from the hide of a young goat

wonder child (verb)	kid (verb)
	be silly or tease one another
	tell false information to for fun