Mbray- dont have your heart set on a character because it isnt your choice. Just go and have fun at the auditions they dont want you acting like a princess, they want to see you. So clear those ideas away- i say that in the nicest way possible but if you have the casting directors i had (they were great!!! But-....) you will have those ideas quickly removed. Also DO NOT wear a disney merch shirtof the character your interested in.
As far as your tattoo, they will take a picture of it if they want you but for me specifically, they didnt even care to take a picture. Its in a hidden spot on my foot but typically they take pics. So take that as you will.. If they like you, they like you