How great, a family cruise!!! You will enjoy the Legend. My wife and I are beach people (live in Florida at the beach) also. If you plan anything, don't miss Tabyana Beach in Isla Rotan. This is one of the most beautiful beaches we have ever seen. White sand, calm and clear water, and a reef about 50' offshore with plenty of marine life to see with just a mask. I would suggest booking that if you book anything.
Also, you may want to try a special night at the Golden Fleece Supper Club. Out of our last five cruises on the Legend, we have eaten at the Golden Fleece 6 out of 7 nights. It would have been 7, but they don't open on the first night. Yes, there is a fee ($30pp) but it is well worth it. Outstanding food and service that is not found much today. Have a great time and see you aboard.
Tim & Beth