Hi there Jennifer, thanks for stopping by the Disney Parks Moms Panel with your question.
I have to admit, I don't have a child with food allergies, but I did do a lot of research regarding your question. Taking a look at the
Frozen Ever After Dessert Party menu, there does seem to be several options which don't include peanuts like fresh fruit and cheese fondue and all of the fun beverages. I also found out, that you can request an allergy friendly dessert plate, which includes about 6 items that will be completely safe for your little one to eat, at the time of booking. On top of that, once you arrive at the party, a Disney Chef will come out and walk the buffet with you pointing out what is safe for your child to eat and what is not. You are right, Walt Disney World does do a fabulous job of being so inclusive to people with all types of food allergies. It's just another reason to love vacationing there. Have you ever checked out the
Special Dietary Requests page of the Walt Disney World website? If not, I'd suggest checking that out before your trip. Also, if it were me, I'd reach out to the Special Diets team at special.diets(at)disneyworld.com before booking just to be sure you would be getting the full experience and value of the dessert party.
I hope this helps point you in the right direction! If you have any other questions, please come back and ask.