Just an entertainment suggestion:
1.) Can you splurge on a cheap portable DVD player? Perhaps one with two headphone jacks? You don't necessarily need a long life battery, perhaps one with an wall adapter and play some DVD's at night or afternoon quiet time.
I am not positive on this ship, but the television may have input RCA jacks that may be able to with bringing the proper cables (assuming DVD player has output) play the DVD player and have the DVD thus play on the tv screen in cabin.
2.) Not sure if the girls are into simple Atari type video games but Target and Best Buy type stores now offer some of the old games on just a joystick size self contained box with RCA cable inputs for $15-30 each with many games on them. Again this is relying on the tv having inputs. Maybe someone who has sailed this ship may know.
3.) Bring along portable kids type cassette players/walkmans and check out books at library a bunch of books on tape for them. Or painstakingly narrate some of the books they love onto cassette tape like you are reading them a nightime story.
4.)Get some disposable cameras and assign a camera to each girl. "Allowing them one or two cameras for the trip"
5.)When our son was 5 in Disney and wanted soveniers he was allowed ONE selection per day that kept his selection rate very special and quite thoughtful. That may come in handy when port shopping.
6.)Go to a store like the Dollar store bring pails, shovels basic beach toys. Less expensive that way for play and seashell collecting. Plus not a requirement to pack for return trip. Don't forget ziplocs for their collectibles.
7.)Not sure of their swimming abilities: arm floaties have always made me very nervous, perhaps bring the zip up swimming vest or now the swimsuits with vests or tubes built in. That way you are at ease near pools, and beaches. Don't forget swimsockls for the feet as sand can be very hot and some shores rough. Plus ship frowns on bare feet so they will at least need sandals.
8.)Don't forget simple snack items they really like: roll ups, cracker paks etc. for those outtings away from the ship.
9.)Bring some 16 oz. bottled water and refill on ship as needed for off the boat shore trips.
10.) Ocean and pools are saltwater perhaps goggles for the girls.
Hope these are helpful ideas.
Adventure of the Seas RC April 2008
Carnival Liberty April 2007
Carnival Miracle April 2005
Carnival Destiny June 2001, July 2005
NCL Southward June 1985 Honeymoon!