WDW has in place an excellent source of information for guests traveling with allergies.
First, start by reading the information on
Special Dietary Requests.
Second, you should call or email the Special Diets department. The information is at the bottom of the above link.
A form will be emailed to you. After filling out this form, it is sent to the Chefs at the dining locations that you have noted on the form. Therefore, you no longer have to call each restaurant.
You will also receive information on counter service foods.
While at WDW, feel free to ask to speak with the Chef. They will explain what your daughter can and can not have from the menu. They will suggest meals that they can specially prepare for her, including alternative desserts.
I would inquire with the Special Diets department regarding your concern about dining at Boma's. I have heard other guests say that the Chef was very accommodating at this location with walking the buffet line and showing what the guest could have and/or preparing an appropriate alternative dish. For severe allergies, to avoid cross-contamination at buffets, a plated dish of food is often prepared for the guest. I would let Special Diets know that you are worried about smell and touch as well as taste.
When you arrive each restaurant, remind the Cast Member at the podium that you have Special Dietary Requests. Perhaps being seated far away from the buffet line would be beneficial.
I wish your daughter wonderful and safe meals at WDW!