Welcome aboard, Ana Lucia! Your cruise aboard the Disney Dream this December is going to be a very magical one, and even more special that month, as the Dream should be all decorated for Christmas by then!
Your cruise includes all of your food and beverages, with just a few exceptions. If you choose alcoholic beverages or certain other drinks like smoothies, those will cost extra. The Dream has two
Adult Exclusive restaurants that charge an additional fee as well, but I highly recommend trying one of them! Palo and Remy are two amazing dining experiences that you will be very pleased you had the opportunity to try! Palo is my favorite spot on all four of Disney's ships.
In addition, if you choose to take any of Disney's Port Adventures, you'll want to set some money aside for those. And of course, souvenir money is a must, as the shops onboard the Dream are stocked full of fun things. I'm sure you'll find a treasure there that you can't pass up!
Be sure to budget in money for tips as well. These can be pre-paid or settled on your account the last evening of the cruise. Typically, servers are tipped $4/day per person, Assistant Servers $3/day per person, Head server $1/day per person, and Stateroom Host or Hostess $4/day per person. This means that you tip this amount per person in your stateroom, including children. Of course, you may always choose to add a bit extra if one or more of those Disney Cast Members really goes above and beyond for you!
I hope these give you a few ideas of what else you might need money for, Ana Lucia. Enjoy planning the rest of your Dream cruise, and let me know if I can help you with anything else!