AD356
I get the feeling that there's more to this story than you're willing to tell. That' OK, you don't need to air all your dirty laundry if you don't want to. Just don't fool yourself that it's all about her smoking. People leave their spouses because they got cheated on. People leave their spouses because they get nagged all the time and can't take it. People leave their spouses because they don't feel love anymore, and being married is no different than being alone except they have to deal with some stranger hanging around. People don't leave their spouses because their spouse has a (known prior to marriage) addiction that doesn't affect the marriage in a horribly negative way. Alcoholism, that destroys marriages. Shooting up, that destroys marriages. Coke, that destroys marriages. Has she ever gone out on a smoking binge, and left you and your child to starve for a night? I doubt it.
Sounds to me, like the smoking is an excuse for a bigger issue. It's causing frustration for you, because it makes it more difficult in your own endeavor. That's understandable. But, look at the bigger picture. If you really love your wife, then figure out a way to make things easier on yourself, or just rough it out until you don't care anymore and smoking is a thing of the past for you. This just started for you. Give it a while. If she's still smoking like this in 5 to 10 years, and you're not. Then her eyes might open up. I would have smoked for the rest of my life, had I not lost my job. For the first month and a half, I was smoking instead of eating. Then, I found E-cigs to be a cheaper alternative. That was my journey to quit. You have yours, and she may or may not find hers. Doesn't mean she's going to die in 20 years because you quit smoking and she didn't. I'm 45 and not dead yet. I probably wasn't going to die in 5 years either. Good luck to you.