You say she's gorgeous, but do you still think she's gorgeous with a cigarette against her lips, or is that the dealbreaker?
Is her personality NOT 'gorgeous'? Do you get on with her? Do you see yourself sat on a porch with a 70 year old has-been-beauty-queen who's lost her looks and has nothing of substance upstairs?...Or someone who you could chat with about anything and everything irrespective of how they may once have looked? My partner is not what I'd call 'gorgeous'. He is not really my 'type' in the looks department (he knows this and is OK with it). I was not in the slightest bit attracted to him physically when we met. I got to know him as a friend and the more time I spent with him, the more I realised how much of a good, kind, considerate, nonjudgemental person he is and how much I enjoyed his company, to the point where I realised I needed him in my life as my constant companion. Then I noticed the good parts about his physique and felt the spark of attraction. This guy is the one person I've been able to tell ALL my secrets to, I never tire of his company.
We have a saying in Britain "I wouldn't kick him/her out of bed for farting". Would you kick her out of bed for farting/smoking/burping/morning breath? If you would then I'd suggest quitting dating, 'cause POBODY'S NERFECT dude!
What more important? Dating someone who very occasionally (let's say for arguement's sake) smokes socially about 6-12 times a year on holidays, the occaional cigar after a meal or with the groom at a wedding reception? Or dating someone who doesn't smoke, but maybe smoked 40-a-day continuously for 10 years (which would moderately impact on health in the long-term) and quit?
If it's the smoke itself that bothers you more than anything above, perhaps she'd compromise with an e-cigarette? Better still, maybe you could compromise to just let her do it if she really feels she needs to so long as you don't have to passively inhale - there's such a thing as breathmints/mouthwash, Febreeze and deodorant!