Your Disney trip begins before you even leave the house. Plan to bring a stroller for your child. Bringing your own distinctive stroller is easier than renting one at the park, because all of their strollers look the same. You may leave it at a stroller parking area and come out of a ride to find it gone. Even if your child normally walks, Disney involves miles of walking, and your child will get tired. A stroller is also a great place to stash stuff that you are tired of carrying. Bring a backpack or diaper bag large enough for diapers and wipes, if your child still wears them, as well as a change of clothes for your toddler. Accidents happen, especially if you have been standing in line for an hour. Also, some rides splash a lot of water.
There are some rides that are better than others for toddlers. You should know how tall your child is before going, so that you don't wait in line for a ride that they are too short to ride. Although not technically a ride, the monorail that goes around Disney from the different parks to the hotels is a great place for toddlers. They love the slow pace and the experience of riding a 'train' above ground. It is air-conditioned, as well. Most of the rides in Fantasyland are geared toward children, especially It's a Small World and the Dumbo ride. It's a Small World is nice in the afternoon, because the ride is air-conditioned, slow and roughly 10 minutes long. There are several places around the park that are similar to playgrounds. This will allow your child to run free and expend some energy, especially if she has been in a stroller or standing in line for a long time.
Be sure to rest throughout the day. This might mean going back to the hotel for a nap during the heat of the day or finding a shady spot in the park to enjoy an ice cream. Pack juice, water and snacks to bring to the park. You can also pack small hand-held toys or coloring books for your child to play with while waiting in line. Take a picture of your child each morning on the way in to the park. In case your child gets lost, you'll have a photo to show to security in the clothes that they are wearing. Always put identification on your child, whether it is in permanent marker on their skin underneath clothing or a luggage tag attached to their belt loop.