Hey Howdy Hey, Anna!
You've Got a Friend in Me here at the Disney Parks Moms Panel, so I'd be happy to help answer your question!
The Disneyland Resort is SO accommodating when it comes to families with babies and children of all ages. You are more than welcome to bring your nursing pump into the parks for all of your baby's needs. In each park you will find a convenient
Baby Care Center where you can pump, nurse, feed, or change your baby in a semi-private space. I recommend bringing a small cooler to store milk with a re-freezable blue ice pack. I also recommend
renting a convenient locker in the park to store your pump and cooler of milk. I did this when I was a new mom visiting the Disneyland Resort, and I loved that these lockers are one low price per day and can be accessed as often as you wish.
Did you know that even the smallest infant Guests can ride on most attractions in the parks? Any attraction that does not have a posted height requirement means babies are allowed to sit on your lap. This means you can experience classics like Pirates of the Caribbean, "it's a small world," Peter Pan's Flight, and so much more as a family. I can't wait for you to create your baby's first Disneyland Resort memories on your vacation.
Please return if you have any other questions, and have a Zip-a-Dee-Doo-Dah day!
-Jennifer