Why did Grandma go to all the trouble for Shotgun's wake and funeral?

Grandma Dowdel went to all the trouble for Shotgun's wake and funeral presumably for two reasons. First, she resented the intrusion of outsiders into town affairs, and the reporter's seemingly patronizing air left her irritated at his presumptions about country folk. Second, Grandma Dowdel was a private person, and she also resented her fellow neighbors' infringement into her private affairs.

While it isn't initially clear what Grandma Dowdel had hoped to accomplish by inviting her...

Grandma Dowdel went to all the trouble for Shotgun's wake and funeral presumably for two reasons. First, she resented the intrusion of outsiders into town affairs, and the reporter's seemingly patronizing air left her irritated at his presumptions about country folk. Second, Grandma Dowdel was a private person, and she also resented her fellow neighbors' infringement into her private affairs.

While it isn't initially clear what Grandma Dowdel had hoped to accomplish by inviting her fellow neighbors to the wake, we do know that she greatly capitalized on her cat's antics during the night vigil. Accordingly, Grandma Dowdel's cat had entered the coffin of the deceased man unobserved. So, the vigil attendees were suitably terrorized when the hearse cloth began to move, seemingly of its own accord.

The moving cloth gave the impression that the deceased was desperately trying to retrieve his hold on life. The incident so terrified the mourners that Grandma Dowdel seized the moment to add to the already charged atmosphere. She grabbed her Winchester rifle and fired off both barrels over the tops of the mourners' heads. The reporter, having had one too many beers, was rudely jolted out of his stupor by the tremendous commotion. He leaped out the window, screaming at the top of his lungs that a dead man had come back to life and that Grandma Dowdel was shooting at him.

Of course, the reporter was never heard from again, and the text tells us that Grandma Dowdel was visibly pleased with her prank. Also, because of the affair, Grandma Dowdel had managed to frighten away her worst enemy, the inimical Effie Wilcox. Effie is also never mentioned again after the incident. The story of Shotgun Cheatham's wake gave Grandma Dowdel a fearsome reputation among her neighbors. As a result, she was left well alone by outsiders and neighbors alike; the old woman had earned her right to peace and privacy.