Who is Agatha Hagglethorn from Grave Peril and what is their importance?

Agatha is a ghost who has been trying to kill the babies in the maternity ward at Cook County Hospital. In life, Agatha killed her own child when she smothered it in an attempt silence its cries while hiding from her abusive husband. After her child's death, Agatha killed her husband and took her own hand..... the hand responsible for ending her child's life. Harry and Michael destroy Agatha at the hospital.