Hi Carrie!
How exciting that your trip is only weeks away! Coronado Springs Resort is a quiet, serene retreat. I think you've made a great pick for your family. All of the Disney buses and monorails are wheelchair accessible. The Cast Members who operate the buses and monorails will be able to assist you in helping you to get your daughter safely on and off. Some of the boats are not ECV or wheelchair friendly (this generally applies to smaller shuttles that run between resorts), but many are, and you will be able to take another form of transportation in the areas where boats won't work.
If your daughter is not able to wait in line for prolonged periods, I would recommend stopping by Guest Relations at whichever park you visit first. (At the Magic Kingdom, Guest Relations is located inside City Hall on your left as you enter.) If you explain your daughters needs to the Cast Member, you can receive a Guest Assistance Card which will enable you to access attractions via an alternate entrance. In most cases, this will allow for a much shorter wait. Some families with children with special needs find that bringing a doctor's note expedites the process of obtaining a Guest Assistance Card, but it is not necessary.
If you have additional questions that I haven't answered, click
HERE for Disney's site for guests with disabilities. In addition, the external website
www.allears.net has some great tips from families who have traveled to "the World" with kids with Autism. If you're interested, simply search "autism" from the home page.
I hope your daughter has a Disney trip that is as magical as she is!