Elizabeth Banks smoking in this

Banks may have wanted to make that choice for her character. I'm sure they discussed it but smoking is no longer something a director can make an actor do.

ETA:

Had to go back and look to find the scene where she smokes, she looks a little awkward but I didn't notice it the first time. I think it's just the one scene so maybe they decided to disguard her smoking.

its a disgusting low life white trash habbit, but she was playing a white trasher.
movie sets have fake cigarettes for non smoking actors