I know on many a long jfk-fco, jfk-mxp and ord-cdg vv there are many a warning about smoking in the lavs and there are many passengers who run in light up, puff once and then extinguish.
I have never seen any one really busted.
I can't imagine a 16 year old girl being so addicted to nicotine that she would need to light up on a 2 hour flight.
As for your tax dollars, I can't really comment. Those are the rules and since they identified the culprit, they need follow the rules.
lala