Re: How can I get my girlfriend to see how badly she needs to quit smoking?
Sometimes getting adversarial is a good plan. Nothing shows her you love her more than you getting upset with her. After all it is for her own good.
Smoking ages you quick. I can spot a smoker a mile away. They stink and they look bad. They should make something you can take that makes you violently ill if you smoke.
I truly despise tobacco products and especially the whole government/tobacco industry for poisoning the public.
Unfortunately, you don't have a whole lot of control here. If you don't plan on marrying this person, just accept it. If you do want to marry her...try dumping her for a bit. Make it clear that the reason is cigarettes. If she changes, get her back. If she doesn't...move on.
I know that's easy for me to say, but these are the kinds of bad choices that can be avoided. She is not the only person in the world that would suit you.