It would seem that the demons cast out of Mary Magdalene eventually ended up in the type writer of that DaVinci Code guy, and were multiplied by the foolish (sadly many even self professed Christians) who read his unintelligible little piece of exploitative fluff (O.K. "fluff" isn't really the first world that kind to mind).
Even without the idiocy of Dan Brown and his readers, Mary had for most of Christian history, been mistakenly focused on as the "worldly" woman of Luke 7:36, instead of being remembered as the first person to whom the risen Christ appeared.
Father W.J. Harrington, O.P., writing in the New Catholic Commentary, says that “seven demons” “does not mean that Mary had lived an immoral life—a conclusion reached only by means of a mistaken identification with the anonymous woman of Luke 7:36.” Father Edward Mally, S.J., writing in the Jerome Biblical Commentary, agrees that she “is not...the same as the sinner of Luke 7:37, despite the later Western romantic tradition about her.”Mary Magdalene was one of the many “who were assisting them [Jesus and the Twelve] out of their means.” She was one of those who stood by the cross of Jesus with his mother. And, of all the “official” witnesses that might have been chosen for the first awareness of the Resurrection, she was the one to whom that privilege was given.
Above from "Saint of the Day"
I have often prayed that the Lord would take these demons from her, but have been shown time and time again, that her presence reveals our own demons . . .those of wanting a perfect little sterilized church, where the music is pretty, the homilies are innocuous, and the service is short enough that I can still catch up with friends for a $50 brunch. By being placed in the same church,God uses this "Mary" to reveal the pharisee living in each of us, and with a not so gentle reminder that all of us are broken, and that one day, Praise be Jesus Christ, all will be restored.