My DD

turned six on our last trip (which was also our first). She, too, worries about other people in movies, especially if her favorite is in danger, and even more especially if a child is about to be separated from his or her parents. (The worst? After pestering me for months to show her the 1976
Superman, she started screaming in the beginning when she realized that Kal-El was being sent away from his parents forever.

)
Anyway, she didn't have any problems with anything, really, in WDW that she was willing to go on. She refused to do Test Track, Splash Mountain and Tower of Terror. (She's anxious to do them this year.) She did not like Snow White's Scary Adventure (which I certainly don't recommend for your daughter). She was fine with everything else, including It's Tough to be a Bug.
If loud noises are a problem, there are lots of them at WDW, especially on the rides. Your best bet might be the silicon ear plugs available in any drug store. They mold easily, pop out easily, and filter out a lot of noise. They don't do as good a job as some of the safety ear plugs I deal with at work (I'm in the office of a maintenance facility, to put it simply), but I don't know if those come in the right size for a child, and I don't think you want to lose all sound.
Of course, Magic Kingdom has lots of rides for her, including Winnie the Pooh, the Dumbo ride, It's a Small World, Peter Pan (might have some problems there, with Hook capturing the Darling children, and then being chased by the crocodile), etc. I agree with another poster - keep telling her that it's all make-believe, and that, with Disney, nobody really gets hurt (not true, given some of their villains, but she doesn't have to know that) and the good guys win at the end.
Good luck. Have a wonderful time.
