Welcome aboard, Kay! What a wonderful 21st birthday surprise you have planned for your lucky daughter! I am so excited for you to enjoy this magical cruise together!
Check out the
Passports and Cruise Documents page of Disney Cruise Line's website, so you have the proper documentation for each of you to sail. On a closed loop cruise from the U.S. like this, a U.S. citizen will simply need a valid U.S. passport, or instead of a passport, their valid government issued driver's license AND state-issued birth certificate. As long as you have read the details on that page and are sure you have the proper documents, you're all set.
Now, once onboard, each guest will use their Key To The World Card as a charge card for any extras like alcoholic beverages. Since your registered guest information is tied to that card, there is no need to carry a driver's license once she is 21, as it will show that information when the card is scanned. Disney makes it really easy, since all you really need to carry around the ship is your Key To The World Card (and your camera of course!) If this is your first cruise with Disney, you may consider purchasing prior or once onboard a lanyard to wear that will hold your Key To The World Card. If you've sailed with Disney before, you are a Castaway Club member and all club members automatically receive a club level lanyard upon check-in at the port.
Be sure to download to your mobile devices the
Disney Cruise Line Navigator App. Besides the schedule of events and activities that you can access on it, it also includes character greeting times and location, a map of the ship, menus, and a fun texting feature that allows you to text through the app and keep in touch with each other onboard the ship. A very happy birthday to your daughter, Kay!
Marcy