Role in the film
She is the sister of Sarah and Mary Sanderson. She is the oldest and most intelligent of The Sanderson Sisters. She loves her spellbook. Back when she was alive, her lover was Billy Butcherson, but she found out he had an affair with Sarah. Enraged, she poisoned him and sewed his mouth shut with a dull needle so that he could not reveal her secrets even in death.
She sold her soul, and possibly the souls of her sisters, to Lucifer for a spellbook of evil magic, containing a recipe for a potion that would enable them to suck the youth from children and maintain their own. Such a child was Emily Binx from whom they sucked her dry of her youth so that she died of being so dramatically aged.
For this crime, along with their refusal to reveal what they'd done to Emily's brother, Thackery (whom they'd turned into an immortal black cat), the Sanderson sisters were condemned to be hanged, but Winifred warned them that in time, on Halloween when the moon was full, a virgin would light the Black Flame Candle and summon them back from the dead.
Eventually, this prophecy was fulfilled when Max Dennison lit the candle 300 years later. The sister then tried to abduct him, his sister, Dani, and his crush, Allison, in order to suck the lives out of all three of them, specifically Dani. With the help of Thackery and Billy, the kids eventually defeated the sisters.
Media: Hocus Pocus
Characters: Winifred Sanderson | Mary Sanderson | Sarah Sanderson | Max Dennison | Dani Dennison | Allison | Thackery Binx | Billy Butcherson | Dave Dennison | Jenny Dennison | Emily Binx | Ernie | Jay | Elijah | Mr. Binx | Mrs. Binx | Miss Olin | The Devil | The Devil's Wife