Ahoy, Joanna!
Congratulations on your first Disney Cruise Line vacation! You and your sister are in for a vacation to remember when you sail with Captain Mickey and his crew.
You'll absolutely love the
Disney Dream. It's a gorgeous vessel, with lots to do for all ages. My favorite spot on the ship is Senses Spa and Salon - a luxurious retreat where you can get massages, facials, skin treatments and more. It's the ultimate place to pamper yourself during your cruise! Make sure to check out the spa on your first afternoon onboard - they have specials and raffle drawings for free treatments.
Your sister is more than welcome to wear swim shoes on the
AquaDuck water coaster, as long as they are the type that will stay secure on her feet. Loose articles are not permitted (sunglasses, cell phones, etc) as they could fall and damage the slide or the rafts.
I hope this helps with your planning! Come back and visit us here at the Disney Parks Moms Panel if you have more questions before you set sail.
Have a magical day! - Diane W.