Hag or Witch was a name used to describe a healer in medieval times. Their profession was demonized. They were shunned by all. Yet they were secretly patronized for their knowledge of cures and many illnesses by both rich and titled as well as the poor. Many of the herbs held a fine line between life and death and were used to heal a loved one or kill an enemy.
Mostly women sought to learn the work of herbs and potions out of necessity for survival. Orphaned or abandon by their families because they were female and believed to be of no value, they had no choice. It was a solitary life. They were not welcomed in any community but tolarated just outside for the relief of pain and lives they saved. Payment was always made in some form of money or goods. The reciever of care feared to be in debt to a witch.
Just such a character comes vividly alive in Karen Stokes' award winning novel "Talion: A Medieval Mystery". Darkess learns the knowledge needed for the means to eliminate any who get in the way of her quest for riches and title. Darkess has no fear of the Hag and eagerly takes advantage in securing what she needs to accomplish her goal.