Originally Posted by
anvilhead 
kim - why not use this exact subject in your convo with your niece. tell her, LOOK i'm scared for you cuz i was a dum dum and now look at what i'm facing???
I agree. If you smoke and are not upfront with her she's going to think "well, you're fine and you smoke.". Be blunt with the trouble you've had quitting, medical and so on.
It may not stop her from smoking but I guarantee she'll think about it everytime she lights up, if you are completely venerable with her and let her SEE how scared you are for yourself and for her.