Nancy, after posting my last post, I looked at the deck plans of the Glory, there is a childrens pool on deck 12 where the Childrens playroon is, when you register your 4 year old, you could ask them if you might be able to bring your 9 month old up there to enjoy the pool occasionally, of course let them know that you would be in the pool with the child. I always say it doesnt hurt to ask. Hope this helps. Don't know if they will agree, but I would give it a shot anyhow. I know your 4 year old will enjoy Camp Carnival tremendously, most children love it so much they beg to get to go.
Good luck with the baby, and I hope you have a wonderful time.