Who is My Woman from Richard Brautigan's Trout Fishing in America ; the Pill Versus the Springhill Mine Disaster ; and, in Watermelon Sugar and what is their importance?

Brautigan uses the term "My Woman" to refer to his female companion. "My Woman" travels through Idaho and other parts of the Northwest with him, and with her baby. The narrator takes on a paternal role with the child, though we never learn if the baby is his.