Catherine didn't know that her brother Craig was called "Pube" by his friends, but she thought it was funny. She also thought it was a little sad that, in fact, he only had one friend, the local sheriff's son.
She got a chance to talk with the boy before his father dragged him back to the house and beat him black and blue. For herself, Catherine was only in town for a few days, looking to pick up some things and maybe look in on her little brother. She worried about him - he was intelligent, but reckless, and possessed an intensity that could be mistaken for charisma. He was a stoner and a nihilist, and that made Catherine a little uncertain about his future.
His future, however, came to an end when he shot himself with the sheriff's shotgun.
The sheriff's son tried the same thing, but only succeeded in terribly disfiguring his face. When Catherine asked him why they had wanted to do such a terrible thing - not only end their own lives but also inflict such pain and suffering on their families - the boy responded, "Nobody cared."
Catherine flew into a rage, calling him and her brother, "self-obsessed, whining little shits." As far as she was concerned, if they had cared - about their lives, about the lives of the people around them - they wouldn't have tried to kill themselves. She stormed out of the hospital in tears, and was probably instrumental in the boy's remarkable change in attitude towards life.
She is presumed to have returned to Dallas to be with her boyfriend.