Hi R.,
Been there done that from diarrhea and vomiting to scarlet red cheek talisman markings - my son survived and will be 32 in April. You can do it! Real Butter and Canola/Olive Oil are your friends. Any recipe that you can make with margarine/shortening or vegetable oil can be made with their substitution and actually be healthier for all of you in the long run. Yes it is a little more expensive, but totally worth the effort.
If you daughter loves chocolate, be wary of Hershies - they use a lot of soy lecithin to smooth out their candies. Homemade fudge is the best substitute and if you use the sweetened condensed milk with cocoa you don't even have to worry about the texture of undissolved sugar!
School lunches can also be a big problem - much of their shortening is pure soy... concentrated use in cake icings and bread rolls, but soy is also found in the cheese products used to make the school lunch pizzas.
If you have any questions in particular - shoot them my way. I'd be glad to tell you what we did to combat this type of allergy challenge.