Ahh... another future sailor!!
PS All with kids, Mustang makes two kinds. For the older kids, the barrel type shown below is without a doubt the way to go (as Jim has shown). For the younger, I reccommend in the strongest terms, the jacket that has the crotch strap, zipper, and head support. Especailly the head support, because you want to make sure that when they fall in, they come up Face UP and supported out of the water.