This is from the FAQ section of the website:
Sea Carousel - Jazzy Jellies - Swishy Fishies - Ocean Commotion - Flying Fiddler
42" (122 cm) or taller
* Guests under 42 tall must be accompanied by a Supervising Companion (a Supervising Companion is a person 14 years of age or older).
* Hand held infants may not ride these rides.
* Some of the Play Area elements have no height restrictions, but the ones that do vary according to the individual characteristics of that element.
We were there in December and i do remember a mom sitting on a bench seat of the carousel with a wee one and I thought there were other parents standing as well next to kids riding carousel animals (although there are super cheapo seat belts on all the carousel animals). I think the above explanation means no baby babies. Do a google image search of seaworld carousel, I bet you'll find lots of family photos of little kids riding.