I’d do a couple trial runs of this at home before attempting it at Disney. Plan a full day of activities like eating out, visiting the zoo, and going to the park, then try keeping her up a couple hours past her bedtime and see how it goes, both that night and the next day.
My son is five this month and he still can’t stay up past his bedtime. Paradoxically, he becomes a hyperactive mess about a half hour after needing to be in bed, and it becomes so much harder for him to go to sleep. And then no matter when he goes to sleep—8 pm or midnight—he’s up at 6 am. Dealing with a wired, hyper kid at night and an overtired, whiney puddle the next day just isn’t worth it to us, especially somewhere like Disney where he’s already going to be on sensory overload. But all kids are different and yours might be able to handle it better than mine.