Welcome to planDisney, Caitlin! Thank you for sailing by with your question.
My son started cruising as a toddler and was an avid milk drinker, so I understand! In order to go through security, you can only have
nonperishable, factory-sealed items, so unfortunately, the milk cannot be in the sippy cup. Coolers no larger than 12" by 12" by 12" are allowed as carry-on luggage if you want to place shelf-stable milk in there to pour into your toddler's sippy cup after you go through security. There will be milk available in
Cabanas or
Marceline Market, depending on the ship, and in the
rotational dining restaurant serving lunch on Day 1. Disney Cruise Line crew members will be able to direct you to where lunch is located so you can fill that sippy cup with milk!
Milk is also available during dinner in the rotational dining restaurants and via
Room Service. You will have a small refrigerator in your stateroom, so I suggest keeping some there. You cannot bring unsealed items off of the ship as you debark, so make sure that the sippy cup is empty.
Disney Cruise Line has something for Guests of all ages, so I know you and your family will have a great vacation, Caitlin. If you have any other questions, sail back to
planDisney for answers.
Cheers!
JoVonn