I have to disagree.  It is standard to ask if the child has food allergies prior to a playdate.  Also, there are tons of allergen-free food options in markets nowadays.  Ham babysitter is pretending that gluten free snacks don't exist.  I eat gluten free cookies, and vegan treats and they are just as good as the ones containing allergens.  Also, kids WILL eat what you feed them, like apples, carrots, celery.  Fun shouldn't be centered on unhealthy, sugary food.  Whenever we have sleepovers, the kids are too busy playing that they actually forget to eat.    If your child has severe and multiple allergies - the best thing to do is pack their food before they go to a friend's house.  This is what nurse mom should have done, you can't trust hams to do any work that would require them minimal effort, like walk around the market to search for gluten-free options.