Acting Skills
If you want to become a Disney princess or any "face" character (those who show their real face and don't wear a mask) at one of the Disney theme parks, you must have extensive training in acting and, if possible, dancing.
This is because actors are expected to play their part extremely well to create the illusion that it is really them. Characters like Mary Poppins and Alice have British accents, so whoever plays them must have a perfect British accent too.
No Tattoos
If you have any visible tattoos, chances are that Disney won't be keen on hiring you. This rule not only applies to those playing characters but to all employees at the Disney parks. Those who have arm tattoos, for example, must wear long sleeves at all times.
It is understandable when you think about the illusion that characters are supposed to create. If you see Snow White walking around with a huge tattoo on her arm, it would kind of ruin the magic.
Height
The Disney princess audition process may take up to six hours, but if you don't have the right height for the job, you'll probably won't make it past the first 15 minutes. It is extremely important for Disney to hire actors with the right height for the characters.
Princesses must be between 5'4 and 5'7 and not wear a size bigger than 10. They must be between 18 and 27 years old, but those who are 27 are not likely to keep their job for long because that's usually the retirement age of Disney princesses.