DS1 would notice or acknowledge rhymes around age 3, only recently (almost 5) started making up his own rhymes. He's not much of a creative kid, he's much more of a math/science kid. I'm not surprised he'd be on the later end of the rhyming spectrum.
Hi! I'm Shannon
Wife to J
Mama to a couple of crazy boys - L (12/07)
and E (2/11)
and Meatball coming 4/14