Hi there, Jessica!
I am actually at the Walt Disney World Resort right now and I've been on a bit of a scavenger hunt for plus sized Disney shirts myself. I'm afraid that I'm not having too much success with that. What I have found at most of the shops I've had a chance to check out so far are sizes up to 2X. The sizes run small so the 2X is more like an XL. I know this is not the greatest news ever, but I have found a pretty nice selection of
Women's size Disney shirts online available at The Disney Store. What you could do is place your order and have them shipped to you Resort Hotel so you have them when you arrive on vacation! I'm thinking that would be the next best thing!
Also, the Design-A-Tee by Hanes shop at Downtown Disney has shirts there that you are able to design yourself. It's a whole lot of fun and they carry sizes up to 5X! This can be a super fun activity to enjoy with your family and it's always fun to have matching shirts! I answered a question earlier about the
Design-A-Tee shop and included a video describing more about it if you'd like to check that out.
I'm sorry I don't have better news, Jessica, but I sure hope this helps you get all Disney-fied! If there's anything else I can help you out with, please don't hesitate to come back with any other questions!
Have a Pixie Dusted day!
~Jackie