Who is Fay from Post Office and what is their importance?

Fay is Henry Chinaski's common-law wife. She is described as a gray-haired, antiwar demonstrator and aspiring writer. Fay is out to save the world, lives with three children off alimony checks and help from her mother, and has barely worked a day in her life. Her unwillingness to do any household chores annoys Henry, and their relationship is short lived. Fay, in fact, has a child with Henry and moves out shortly after her birth. She later becomes involved with another man and moves to a hippie commune.