I can see your delimma. No sugar, no nuts, no milk, no wheat--I may have missed some, but this is a serious allergy. What will happen when she goes to school?
Can she have corn? Pop corn? I know you can make milk from Soy beans, as well as other soy products.
The granola I make, I put 4-5 Cups of oatmeal in a big bowl, I add corn flakes, or bran flakes, or grape nuts, any cereal that she can eat--if there are any, about 3 cups of that, then I add sesame seeds, sunflower seeds, almonds the amount varies as to how much I have on hand-or if I have it on hand. I'd guess I usually add 1 cup of almonds, and maybe a 1/4 cup of the seeds combined. I also add about 1/4 C. soy flour, and powdered milk, same amount. (All this does is add protien)
Separately I mix 1/2 C. corn oil (or what ever oil she can have-I have found canola has a flavor I don't like so I wouldn't reccomend it in this) and 1/2 C. honey. Spices can be added as vanilla or other flavors--I have found that it doesn't pick up these flavors unless you use a lot! Pour this over the dry mix and mix it well with your hands disposable plastic gloves work well--it doesn't stick. I put it on the Pampered Chef bar pans they are the ones with a lip around the edge. I put parchament down first, bake for about 10 minutes in a 350 degree oven. Let cool in the pans. You will find that they break up into larger brittle pieces. If you like dried fruit add it now. It will burn more quickly than the cereal.
I have also tried recipes that call for orange juice or water. The time in the oven is longer and it is a moister mix I have found.
I think the only things you have to have is the oats, oil, and a sweetener. The honey lets it coat well, and gives it a mild sweet taste. With just honey and oil and grains, you need to watch it, it will burn easily.
I don't know if you can use any of this, I know that there are artifical brown sugar, and syrup too I think--you could substitue maple syrup, but I think molasses would be too strong.
Are her doctors able to give her shots or anything to help open up her food world?