My wife is allergic to smoke, so I understand your plight. On two cruises we had to change cabins due to smoke making her sick. On quantum class ships, the outdoor smoking are supposed to be deck 5, starboard and on the lido deck (14) port side. Also, unless you are on a cruise out of Southampton (where the ban on indoor smoking extends to cruises departing from the UK), Deck 2 aft is contaminated by smoke from the Casino, so avoid The Grand and Chic MDRs if you can or ask to be seated in the outside aft areas. The music hall is not to bad, but if you are spending a lot of time there (eg. a performance) you might consider sitting in the upper deck.
Check out this video of 6682: