Helgrotha was amongst the first generation of Nephalem to walk Sanctuary. She had been nearly as powerful as Rathma and she watched over those creatures who lived during night as opposed to the day. She had been kind, but also firm in her protection of those for whom she had cared.
She was presumably slain by either Lilith or Inarius. Helgrotha's spirit first accepted Mendeln as a Keeper of the Balance, giving up one of her bones to act as a spiritual focus.