You will be able to board at 11:30am if all goes well. If your flight arrives at Orlando at 10:30, I would bet you will make it on board at about noon or soon after.
I agree, though, get on ASAP and learn the ship layout. I'm not sure about kid stuff, but there seems to be plenty of stuff for kids to do, especially with sports and such, and of course the pool.
Study your Compass each day and hi-lite the activities that interest you. Of course if you are doing the 4 day cruise, you have only 1 day at sea, so probably most of your time during the morning and day will be at CoCo Cay and Nassau.
Go with an open mind and just enjoy yourself.
Sovereign of the Seas 12/22/02
Sovereign of the Seas 04/27/03