Yes. Melissa Joan Hart smokes cigarettes in real life. You can find pictures of her smoking at Celeb Smokers.
The Daily Mail reported in September 2013 that Melissa Joan Hart has revealed that beneath her girl-next-door veneer is a torrid history with drugs. The former child star, who became famous on "Sabrina, The Teenage Witch", has written a tell-all book about her wild youth as a Hollywood starlet.
Among the many recreational drugs the actress experimented with as a young celebrity were Ecstasy and magic mushrooms.
Of interest, see a gallery of celebrities who like to smoke on TheHollywoodGossip.com.