Hello Arnel and welcome back to the Disney Parks Moms Panel!
Tell your daughter that this IS a great question. I just returned from a Walt Disney World vacation with my vegan daughter and I can assure you that there are numerous dairy-free "ice cream" treats across the Walt Disney World Resort.
First off, the best news,
Dole Whips and Dole Whip Floats are completely dairy free. They can be found at the Magic Kingdom, Disney's Animal Kingdom, and at Disney's Polynesian Village Resort. Other non-dairy treats including Tofutti and Rice Dream can be found in numerous locations including
Beaches & Cream Soda Shop at Disney's Beach Club Resort,
The Plaza Ice Cream Parlor at the Magic Kingdom, and many other locations. I recommend asking wherever ice cream is sold. I think you will be pleasantly surprised how many have non-dairy options.
I hope this helps with your planning.
See ya real soon,
Anne