People used to smoke, a lot.
In the 1950s I don't think it had become a class marker the way it would, so having all sorts of people smoking is pretty normal. My Gram used to smoke like a chimney (all my grandparents did, in fact). It was a thing one did (although ladies did not smoke outside, walking down the street, she told me). Although come to think of it my USian grandparents did not smoke, and they were a bit snooty...my (step)dad's aunt did though. It may have been more prevalent in the UK/Canada than the US? I don't know. She used to relish sitting down with a cup of tea and a cigarette. My other Grandma was a cup of coffee and a cigarette, lol. They're all dead now, although nothing to do with lung cancer, surprisingly enough.