I'll come at this from the other side as a smoker.
Like a pp I don't smoke indoors.
This is the really big problem you're facing.
I've visited friends baby's in the past, given gifts etc but those gifts don't come from a home contaminated with smoke and when visiting I've always slapped on a patch in the morning to ensure I've not smoked for over 12 hours before visiting (clean clothes etc). Same protocol if they've visited me. I've also told friends what I'd be doing so they didn't have to have any awkward conversations with me.
Where I'm going with this is that it is possible to "share" your baby with a smoker but they have to be willing to the baby first over the addiction.
In your situation the room for compromise is virtually non existent.
Years of indoor smoking means that even if she quit now her home will be saturated with nicotine. It takes extensive work to clear this from a property - in some cases stripping back the plaster.
If she comes to visit you what clean clothes does she really have? Even "clean"
clothes hung in a bedroom where someone smokes still absorb the smell and tar.
The idea she can wear a smoking coat and have a fag outside when visiting makes little difference if the clothes underneath are saturated with cigarette smoke.
You can wash the clothes she gives you, but it's not ideal really.
The only thing I think you can do is say she has to visit you (baby will not go to her house) and on arrival change into a clean outfit that you'll provide (and change back when she leaves so that outfit stays with you so never in a contaminated house). She should not smoke on the days she visits (preferably in the afternoon and you'll get some patches/gum etc to help her with this).
I think that's all you can really do if I'm honest.