When my mother in law finally was diagnosed with stage 4 lung cancer (stage 4 means no hope left in terms of cancer) while she went through treatment to try to extend her life, my father in law quit so she wouldn’t be exposed to more smoke. But when she died in short time, he went right back to smoking at the same rate.

All smokers die a smoking death. Make sure you share this with your sister.

One of my neighbors died in his 70’s and had known him to be healthy and robust and always cheerful. When I consoled his widow I asked if he had been sick and sure enough he had lung cancer. I was rather shocked since I had known them a long time and never known either to smoke so I asked how he got that. She said they both used to smoke and stopped in the early 70’s as soon as it came out that smoking could kill you, but it was too late for him and 30 years later his cancer from it finally developed and he died.

So all that nonsense about for every 10 years you haven’t smoked your risk of a smoking death going down decreases is nonsense. Your sister is PLANNING her death and I would treat it as seriously as her writing a suicide note.

And do not ever go around her when she’s smoking because the effects to you are just as serious.

Take her to see some xrays of a smokers lung compared to a non smokers lung

arrange to take her to a hospital to see people with lung cancer and other things asociated with smoking.

in the source i’ll link some pics of a smokers lung

INSTEAD, I would go a little deeper and lay the "smoking kills" on REALLY thick, explain that you’re going to be crushed WHEN she dies, so she knows that unless she stops, she will die.

I know it sounds harsh but she really needs to know this

http://www.uoregon.edu/~jkullman/Doc2_files/image010.jpg