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

In Watermelon Sugar introduces Pauline, who is the narrator's current girlfriend. She is described as blonde, svelte, and tall. While at the cabins, Pauline acts as the cook for the cluster of cabins where they live. Over the course of the story, we come to see that Pauline is far more concerned about Margaret's feelings than the narrator is. Their affair is short and sweet.