Hi AnnMarie!
Thanks for stopping by with your question. I have an autistic grandson so I know how important it is to choose the perfect time and circumstances for your little Princess. All of the things that you mentioned are hard things to predict at Walt Disney World. For example, there have been times we have visited in December when it has been quite cold and times when it has been very warm. Things like crowd size and amount of rain are also tough things to know about for sure. Crowds are usually lower during the times when school is in session but depending on a number of other circumstances (special events, etc.) that might not always be the case. Here are a few ideas of how to make this the best possible experience for you and your daughter, no matter what time of year you decide to go: First of all, consider staying at a Walt Disney World Resort Hotel so you have access to the Parks during
Extra Magic Hours. Typically, the crowds are lower then. Another thing I would highly recommend is that you stop by Guest Services when you first arrive at the Park. Here you can speak with a Cast Member about a
Disability Access Service Card (DAS) that is available to those who have a difficult time waiting in a traditional line. With DAS you can receive a return time for a Ride or Attraction of your choosing (based on current wait times) and simply show up at that time. Once you have finished that Ride, you can proceed to one of several kiosks located throughout the Parks and request another one. It is a fantastic service Disney offers that you will love!
Please come back if there is anything else we can do to assist you.. By the way, Walt Disney World is my grandson's favorite place in the whole world. I bet it will be your daughter's, as well!
-Nancy-