Oh, tinkerbell15, if you are allergic to soybeans and cannot tolerate even a little bit, then you will have quite a chore selecting foods outside of your own kitchen!
I am also allergic to soybeans. And almost all processed foods contain soy in some form: For example, soy oil, soy protein, soy flour, margarine, mayonnaise, most fried foods (although Disney Cruises tend to fry things in canola oil), most salad dressings.
The way I cope when I travel, is to eat mainly raw fruits and vegetables (with vinegar or wine vinegar, with olive oil if it is available), or to ask for vegetables steamed without any fat, or for broiled meat with no sauces. Then I can add real butter (have to be VERY specific about this) to my vegetables, especially baked potatoes, yum!--but find out whether the skin is oiled before cooking.
But if you are allergic to ?all fruits and vegetables,? then you cannot do what I do. In this case you DEFINITELY need to talk to a nutritionist or dietician about how to find safe foods and an adequate diet. A lot depends on exactly what your symptoms are and how severe. You will learn by trial and error how much you can eat--if any--before the symptoms are too strong to tolerate.
MEANWHILE, I found the Disney Wonder (in particular, my head waiter Ali) to be very eager to provide me with soy-free foods. And they succeeded perfectly!
I wrote up my experience on the Wonder on the disABILITIES board. Here is where you can find my VERY DETAILED description of what I did and of what foods were safe on the June 27 cruise:
http://www.disboards.com/showthread.php?s=&threadid=218887
Be sure to read all the way down to my July 2 post, written AFTER the cruise.
I wish you good luck and good professional advice. You have quite a challenge, but you can do it!