As an iranian born dual national, she is considered moslem, therfore should not have consumed any alcohol.
Moslems are not allowed to hold a liquor licence, so there may actually be a law banning them fom consuming.
Mr and Mrs average westerner dont need to worry about having alcohol on flghts, despite the Daily Mails BS.
i have personally witnessed Iranians being sent back to duty free to refund their alcohol purchases.