Normal
There are several reputable companies offering trips to Stingray City, we used Captain Marvins a few years ago and plan to again this December (fantastic experience, I highly recommend them). Check out NativeWay, Soto's and Captain Bryans (Brians?) too. As for the turtle farm, your children will enjoy that as they are too young to notice or be bothered by the fact that most of the turtles there are eventually used for meat. They do release a small percentage back to the ocean, but not much. We went there once, and got to hold one of the sea turtles, not sure if you can still do that or not, but that was neat and your 4 year old would especially enjoy that. In my opinion, I wouldnt bother going there again, I would rather see these gracious creatures in their natural surroundings, gliding through the beautiful caribbean sea, not in cement vats.