I'm one of the older posters here (let's put it this way--I remember when this comic first came out, and buying it) and I remember my mother, smoking like a chimney, in the car we were in and as a kid watching the wreaths of smoke swirl in and out (and we had no air conditioning in the car) and thinking they were "very pretty".
And my mother, by the standards of the time, was a good mother. If she thought seriously she was endangering her children by secondhand smoke, she would have been horrified.
No, she didn't die of lung cancer, BTW. She did manage to give up smoking in her late fifties or so.