Hi!
You really shouldn't have any problems at all. Most of the attractions at Walt Disney World are designed for the whole family. Sure there are some thrill rides that only appeal to other children and adults, but they are really few and far between. For example, my wife doesn't enjoy amusement parks because she doesn't like intense rides, motion simulators, getting wet, etc, but absolutely loves a Disney vacation.
For example, in the Magic Kingdom, your daughter should be able to do every attraction at the Magic Kingdom, except:
Space Mountain
Splash Mountain
Big Thunder Mountain Railroad
Snow White's Scary Adventures
Stitch's Great Escape
Just the name of the Haunted Mansion attraction might make that attraction too scary, but it really isn't. Some 3 year olds love it, while others won't step in it. My own son, age 6, wouldn't go inside the Haunted Mansion from age 2 to 5!
Be sure to order the free Walt Disney World
planning DVD.
I also recommend picking up the book "The Complete Walt Disney World"
by Julie and Mike Neal. There are a lot of good tour books out there,
but I especially like this for first timers as it is packed with photos
and some good tips; the photos help to get everybody excited for the
trip and give a glimpse of all of the wonderful things to do inside and
outside of the theme parks.
Enjoy planning and write back if you have any more questions!