Practical Magic by Alice Hoffman

For more than two hundred years, the Owens women had been blamed for everything that went wrong in their Massachusetts town. And Gillian and Sally endured that fate as well; as children, the sisters were outsiders. Their elderly aunts almost seemed to encourage the whispers of witchery, but all Gillian and Sally wanted was to escape. One would do so by marrying, the other by running away. But the bonds they shared brought them back-almost as if by magic...