We are sailing the first week of september. I will be very interested in hearing how things work out for you. I liked the back pack idea, but I think at 5 months she will still be too little for it. I use the ultimate baby wrap so I can wrap her on my back if she seems interested.
If you can go to a store and buy your diapers wipes etc once you are in florida. that will make a big difference. If you want to post your packing list or pm me I will let you know what we usually do. This will be the second cruise with our son, but our first with two kids. I think it will just be a little more stuff. and way more fun!