New house, new tenant, new issues (smoking)

[Brandon Smith]

I've recently bought a larger second duplex, the current tenant has been there for 15 years. She smokes inside, pays a very low monthly rent, and doesn't use most of the space. Sucks on my end especially since I don't allow smoking and she underpays on her old month to month lease. Issue is that she's elderly, has many health issues including cancer, lacks financially, etc. so it puts me in a hard ethical decision since she's also basically on her death bed. 

I've recently thought that maybe sticking her in my other duplex soon would be a decent thought since my other tenant will move out soon. It is a smaller duplex so she could keep her same monthly rent, there's no stairs there making it easier on her, just overall a better situation, the only issue is the smoking. This makes it hard on me in general on what to do with this tenant exactly so I just simply don't throw her on the street knowing how hard her life already is making it that much harder. 

Regarding the smoking, I think it would be best to invest in an ozone generator already in general getting into the landlord business. If I would put her in the other duplex would it be as simple as using that ozone generator, then re-painting, and replacing the carpet? Between tenants you already paint and replace carpet so I'm thinking it wouldn't be a big deal.  Just in a bind and looking for opinions, I'd appreciate any suggestions, thanks!