For starters, it's illegal for her to have cigarettes! Either she purchased them, in which case the clerk who sold them to her could lose their license to sell tobacco products (among other punishments), or someone bought them FOR her, in which case that person could be subject to fines, imprisonment, and revocation of driver's license. Perhaps realising that might help her to stop smoking. Is anyone else aware that she smokes? Like your parents or school counsellor?