Curious Symbolical Custom

On Saturday last I married a couple in the parish church. An old woman, an aunt of the bridegroom, displeased at the marriage, stood at the church gate and pronounced an anathema on the married pair. She then bought a new broom, went home, swept her house, and hung the broom over the door. By this she intimated her rejection of her nephew, and forbade him to enter her house. Is this a known custom? What is its origin?