Hi, Mary, and welcome back to the Disney Parks Moms Panel!
Mary, I absolutely love your idea! You're going to have so much fun dressing up with your little princess at Mickey's Very Merry Christmas Party. What a precious memory you're planning!
Normally, adults aren't permitted to wear full costumes in the Theme Parks at Walt Disney World Resort, but there are exceptions for special events like Mickey's Not-So-Scary Halloween Party and Mickey's Very Merry Christmas Party. Generally, you won't be allowed to wear a mask or carry anything that can be construed as a weapon, or wear anything that obstructs the movement of other Guests. You'll find a more complete guide to wearing costumes for special events on
Disney's Theme Park dress and costumes page.
You might find the video the Disney Parks Blog produced a couple of years ago with
costume guidelines for Mickey's Not-So-Scary Halloween Party helpful. It's fun and really helps to visualize what's allowed and what isn't.
Another fun way to dress up without going for a full costume is to try something called "DisneyBounding." It's a style of dress that incorporates elements of Disney characters, like certain colors or accessories, in an outfit inspired by that character. The best way to get more information about DisneyBounding is to do an internet search of the term. But beware - once you start looking at all the great ideas, it's hard to tear yourself away!
I hope this helps you have a wonderful Christmastime at Walt Disney World with your little Cinderella, Mary. Please come visit us again if you have any more questions!
Kathy K.