Apocrypha
According to 3rd party material produced by Green Ronin, the Hag Countess and Lilith are one and the same, a unique being who has changed her name through the ages.
In The Unholy Warrior's Handbook by Robert J. Schwalb, "Lilith" is also known as the Hag. Her servants are listed as Lel, Marquise of the Night, a tribune, and a few generals.
The Book of the Righteous by Aaron Loeb provides a creation myth for this version of the Hag. In this version, she was created from one of the div, beings born of fire at the beginning of time. The text calls her "mother of beasts" and states that countless monstrous races, including giants, trolls, and goblins, sprang from her womb.
Read more about this topic: Hag Countess