My grandmother used to be the same way. She smoked 4 packs of cigs a day. She lived in a trailer park and her trailer was very clean but it was just yellow inside and you couldn't even see when you walked in because of the smoke.
But we were little and we loved her.
She ended up with the same thing and osteoporosis. She had to be placed in a nursing home becasue she had to be hooked to an oxygen tank and her bones were brittle.
She died shortly afterwards. It was sad to see her go through all that, but they are set in their ways and it's up to them to change. If they can't then it's inevitable what is going to happen to them.
My hubby has smoked for almost 30 years. He wants to quit, but he is having a hard time. My kids put signs all over the house for him to quit, my daughter even put his screen saver on his phone to read: "Quit Smoking".
We used to walk on pins and needles, but we don't any more. We tell him like it is. He doesn't smoke in the house because he thinks it smells bad. So we are okay there.
But he's coming along. Our kids are older now, and he still hasn't quit. They have to want to do it themselves.
Your mom should respect your fealings. I know my hubby respects ours for the most part. I would just tell your mom-in-law how you feel. Has your hubby done anything or said anyhting?
Good luck with your situation. It's hard because you don't want to hurt their feelings and yet you don't want to see them later in life suffer.
Best wishes,
J.
J.