I don't think that there is a blanket answer when schools are asked to address allergies in children. People have very strong feelings about the safety of their own child vs the comfort of another, and conversely, the comfort and well being of their child vs the safety of another.
My DGD was allergic to dairy and eggs, so her diet was limited, Thank God it was not so severe that contact was dangerous for her, but she did go to school with kids whose peanut allergies were pretty severe. These were K-2, so little kids. Our school system addresses each issue as it occurs, and for the most part, the parents are supportive. No one has banned dairy and egg from school, and quite frankly, with all the items that include both, I cannot see how they could safely do so. I do believe that if it was necessary, they would try to find a solution, and most folks would try to follow the guidelines.
I think that issues occur when adults do not understand how allergies impact other kids. Children learn from their parents, and in Kady's case, the children were very aware of what Kady could not eat, and "watched" out for her. In her school system, tolerance for differences was taught from the get go, so food borne allergies were just part of the program, addressed individually so you knew who you were supporting, and that was how you were approached...support, not mandate. I thought it made a difference in how parents and children responded.
It is not easy to be "that" kid. No ice cream. No peanut butter cup. No pizza. It goes on and on. For youngsters, it is a hard path, so when a parent reaches out for help within the school system, please don't be too quick to think she has not taught her child about personal responsibility. She may be trying to manage a situation that is a lot more than the child and adults around the child can manage without addition support from the school community, without withdrawing her child completely. Children should not be isolated, and that can happen, I think.
Every day we thanked God that Kady's allergy was manageable, and that she, even as a kiddo, would never touch a thing she did not know to be safe. But I did witness a near miss when I was a parent helper, and that made all the difference to me. One child had severe food allergies, and was never to eat anything not supplied by Mom. One of the room mothers. mixed up her plate, an that the good Lord I saw it, because the child would have believed her food was provided by Mom. I think this is one reason that some parents feel the need to ask for additional concessions. If the threatening food is not there, a tragic accident will not happen. After that incident in school, my DD and this mother always made a point of being at school when there were "special" events that other parents would be monitoring. Working as a team, they were able to ensure the child's safety, and still let her participate in activities that included those outside her classroom.