AITA for telling my sister I won't accommodate all her food requirements?

NTA. Etiquette on accommodating food restrictions is thus:

If it will injure someone to be near the food, like literally it will physically send them into anaphylactic shock for you to have the allergen in your kitchen or at the table, then of course you keep it away.

If they merely cannot eat the food, like they'll get sick if they physically put it in their mouth (whether or not they have a doctor's note or w/e), then your only obligation is to be graceful in accepting a polite "no thank you." Ideally a good host would make sure there's enough different options that everyone can eat something, but one person doesn't get to ban foods they don't like for everyone else.

/r/AmItheAsshole Thread