As you know you can't control her addiction to cigs. She is in charge of her own health.
IMHO- I wouldn't with-hold helping as a punishment or see helping as enabling.
Her own actions may have to lead to dire health conseq. bef she chooses to give up the cigs. She is addicted.
If you choose to help or not I would keep your reasons clear-
out of sense of duty as a daughter or love or because she needs you.
It is not easy watching someone jebordize their health...but we are powerless.
She knows what the smoking is doing.
Have you talked to her Medical doctor about him suggesting a cessation program ??