My best friend was struggling with anxiety issues (long story), but I totally understand what she is going through. She has been going to counseling, but for the last 8 months started dating this guy who is a smoker. She was a social smoker before, but now she turned to a chain smoker. It's so sad to see and I feel like because of all her stress and anxiety she is turning to something else for relief and it's not the right thing for her. It's so unhealthy and because of her given circumstances something she should not be doing. What can I do as her friend? I don't want to be bossy and I feel like whenever you tell someone to quit smoking it kinda makes them do it more.. any advice??

I think all you can do really is encourage her to stop.  There's so many health risks associated with it.  And just remind her of how much better she felt when she wasn't smoking.  A few weeks ago I sort of started smoking cigarettes again and Oh Boy I definitely feel it the next day.  I'll start coughing out of nowhere, it makes my voice raspy and my memory is worse because of the lack of oxygen going to your brain.  It's just a costly, bad habit and it's only going to make her stress worse in the long run.  And also talk to her boyfriend and let him know that he's one of them main reasons that she started smoking.  If you're around smokers, you'll start to smoke more and it becomes a habit.

I also have a friend who is just starting smoking. She is also a social smoker but I feel like its growing more and more, she's starting to crave it and being the one who mentions going outside for a smoke. What I keep doing is continuously telling her that she shouldn't, how its a turn off how she's just going to turn into one of the smokers who smokes and drive because she cant stay a few minutes without one, how its going to damage her health. She isn't listening but I have noticed that she has cut down around me. There's really nothing else you can do but continue mentioning it to her.