DS1 (2.6) appears to be growing out of his milk allergy. I haven't told nursery yet as it's all being carefully controlled, not a general free for all of any dairy foods.
We have to review the paper work every 3 months and list his banned foods and alternatives. His name appears on lists of food issues. Preferences like vegetarians are in black, allergies in red. Nursery have been excellent at dealing with it and I trust them not to contaminate him more than I do myself!
The reaction being mild doesn't mean that she's growing out of it. The proportion of the allergen in the food is low, so she could still have a more serious reaction to loose milk. When doing a milk challenge, you start with something like a biscuit that contains a small amount of milk cooked at high temperature and gently increase the exposure and milk content of foods.
We went to a wedding a year ago and the caterers were well briefed about a number of dietry requirements. We got to the table, a pile of breadsticks was ready (soya intolerance means most bread is out of bounds), he had dry new potatoes served and a jelly for dessert. Great! He tucks in to his dinner, scoffs down his veg. I give him seconds, to find that the remaining veg is sat in a puddle of melted butter.
That was fun at 5 am. For me and all the other wedding guests as he got caried off to the toilets screaming for an emergency nappy change. It was a fun holiday the following week. Thank goodness we had a washing machine at the appartment we stayed in as his bit of diahorrea meant he got through 2-3 times the amount of clothes to normal. Ahh the family memories of our trip to the Giant's Causeway. That poonami and alfresco nappy and clothes change was definately enough to scare the giants away!
Talk to the headteacher. Sounds like they need to remind staff about their procedures or even tighten them up.