Minnie definitely does have style worth mimicking, Thea. Isn't she just the cutest? I completely understand your desire to honor Minnie's fashion with your attire. I'm really glad that you asked about this, though, because there are specific
Property Rules that address this topic.
If you take a look at the Property Rules I've linked to, you're going to want to pay close attention to the section marked "Guest Courtesy and Attire Policy." You'll notice one rule that prohibits guests over the age of 14 from wearing costumes in the theme parks, water parks or the ESPN Wide World of Sports Complex. If the dress you're wondering about could fairly be considered a costume, you may get turned away at the entrance to the park.
Have you heard of
Disney Bounding, Thea? It's the art of using everyday clothing to recreate looks worn by favorite characters. Disney Bounding is a great way for older teens and adults to express some character love without breaking any property rules. A quick Google search will probably yield you some great inspiration for a Minnie-inspired Disney Bounding look.
Once you've perfected your look, you might consider booking a character breakfast at
Topolino's Terrace – Flavors of the Riviera. Minnie is one of the characters that hosts this meal. I can just imagine how cute your selfie would be -- you in your Disney Bounding look with the real Minnie posing in the background.
I hope I've helped, Thea. And I'm confident that you are going to flatter Minnie with your own version of her signature style!