No, not a silly question at all! :) Well, certain parts require different heights…for someone wanting to become Alice or Tinkerbell you have to be fairly short..for the princesses like Cinderella, Belle, Snow White, etc. You have to be around 5’7. But if you look just like the character, height isn’t that big of a factor. Also they look for healthy looking girls. Disney doesn’t want their princesses to look like all skin and bones. Because you are portraying a princess who is from the ages 12-18 or so, they want someone who has a “young look”. And it turns out eye color doesn’t matter, because most people don’t remember the color of the princesses eyes. You should look up the audition calender, and try out! I hear it isn’t that bad…they are looking for people who have a lot of expression and can portray emotions with their body. Because of the elaborate costumes and make up the face characters have to wear, they want every movement to be BIG.
I am very interested in it too, but I have to wait till I am eighteen.. You should really audition though, if you are interested. It seems like a lovely job! I hope I have answered your questions :)