Neck fan / neck air conditioner
Portable handheld fan - this is nice to keep in your bag for being in ride lines or other places where you can't have the stroller
Misting bottle/fan - kids love these ones (these are for sale in the park but its way more money there)
PONCHOS! - You could certainly do packable rain coats as well
STROLLER COVER! - Strollers must be parked in central locations for most rides, and you never know when its going to rain
Stroller fans - one for her and one for you
Reusable shopping bag - Strollers cannot be open on the bus - you will need to collapse your stroller. I recommend having a LARGE reusable shopping bag that you can quickly toss all your stroller stuff into when you have to collapse
Stroller toy teather - To keep sippy cups and snack cups from hitting the ground when they are thrown
Power bank - You will be using the My Disney Experience App throughout the day and need to keep charged! You will also have digital park touring guides you need to access.
Disney has FuelRod
Refillable water bottle
Snacks - Disney will actually allow you to bring in a soft-sided cooler but no loose ice
Autograph Book + Click Sharpie
Pre-purchase a bubble wand
Swim Suit - pool towels are provided at the pool
Pool floaty if you need a specific one - Disney does provide lifevest style floats for all sizes (kids)
Charging Station (I use one like this https://www.amazon.com/Protector-Extension-Multiple-Extender-Essentials) with phone chargers, etc ready to go
Sound machine, if needed