Don't blame the paint or your Mom for your daughter's allergies. Some people are just genetically pre-disposed to being hyper sensitive to certain foods. They may or may not outgrow them or they may develop new allegies as they grow older. My middle child loved shellfish: shrimp, crab, clams... and all of a sudden he had a severe reaction to something after eating out one evening, so bad we were in the ER. Come to find out after testing he was allergic to shellfish. We also found out he had other environmental allegies to grasses, various tree pollens, dust, molds, dust mites... the air he breathed. He has become less allergic to the environmental things, but shellfish is still a big problem. He was 12 when this happened. My husband is allergic to shellfish, my Mom has a sensitivity to eggs, milk and chocolate, and I get all stuffed up during the spring when pollen from trees and certain flowers is in the air.
Let go of the anger, it won't do any of you any good, at all. Concentrate on damp mopping your floors and keeping the dust down. Nut allergies are frequent amongst a lot of people, especially kids, so get label conscious. Get her a medic alert bracelet and keep epi-pens handy when you go out to eat or visit with friends. If she's in pre-school, make sure the school has one for her in case of emergency, i.e. a severe allergic reaction. Talk with your pediatrician or allergist about preventive measures and emergency actions to be taken (epi pen, when and how to use).
Each and every one of us has a level of sensitivity to a variety of things we eat, wear, and breathe. No one is to blame, it's what makes us unique. In our house, it just means that there's more crab or shrimp for my other two kids and me to eat! :o)