What's the name of the film with a dead little pilgrim girl?

I think it was made in the early 1970s. I haven't seen it in years and don't remember most of it. It was about a pretty blond woman with a baby who was haunted by a dead little pilgrim girl that was either a ghost or a witch. The evil little girl wanted the woman's husband. The film took place in the countryside in contemporary times. Does anyone know what movie this is?