Hi Isabell. I've been visiting Walt Disney World with my daughter since she was a baby. It is a very awkward stage to be in while on vacation, I've been there - done that.
Funny story. We were in line for the Magic Carpets of Aladdin when my newly potty trained daughter just couldn't wait and of course I was trying to push the limit because we were about to get on the ride. Sure enough, after the ride we are hustling to the nearest restroom and a very funny pirate near Pirates of the Caribbean looked at me and yelled, "There she blows...." in his best pirate voice and in that moment I knew I was too late. Unfortunately, there isn't a great solution to this situation. My best advice is to familiarize yourself with the park maps and where the restrooms are located. Another great spot to locate at each park are the
Baby Care Centers. In these areas you will find private areas where you can change her and clean her up if there is an accident and restrooms. If you do choose to put her in diapers, you can change her in these Baby Care Centers. If something has a long wait time, take the extra few minutes before getting in line and take her to the restroom. I also always packed an extra outfit or two in a ziploc bag in case of accidents. This was really helpful because I was able to put her wet clothes back into the bag so it wouldn't get on anything else.
I hope this helps give you some insight. Use your mama instinct and do what you think is best. If you have any other questions, please do come back and ask.