Hi Anne!
Every time I hear that a Guest is going on their first Disney cruise I want to squeal in excitement! I'm not exaggerating either...go ahead and ask any of my Disney Moms Panel friends...I'm loud! The Disney Dream is aptly named and you are going to get hooked on Disney cruise vacations. Just warning you...you'll want to book the next one before you're even off the ship.
Now, the beauty of cruising is that you are not tied to any particular activity. If you want to stay onboard during a port of call day, you are certainly welcome to do so. There will be plenty of activities scheduled for your entertainment, and if you just want to relax, this is the perfect time to hit the spa because most Guests are off of the ship.
I love beaches so don't miss Castaway Cay! You can have relaxing adults only time on Serenity Bay while your daughter is very well supervised and having a blast at Scuttle's Cove. In Nassau, I recommend taking part of
Atlantis Beach Day. Not only do you get to enjoy one of the Bahamas' beautiful beaches, you get to explore Atlantis Resort on Paradise Island. It has the world's largest open-air marine habitat; my son LOVES it! It's great for kids your daughter's age.
Please let me know if you have any other questions. I'd love to help you plan your cruise and make it the best that it can be! Happy sailing!