What is the importance of the jigsaw puzzle that Holly made for Audrey Millard in the novel, The Whole Enchilada?

Prior to becoming well-known for portrait-collages, Holly had created and sold hand-painted jigsaw puzzles. Although she had given up making these puzzles several years prior to the start of the story, she makes one shortly before her death and gives it to Audrey Millard, the church secretary at St. Luke’s, with instructions for Audrey to give it to Father Pete if anything happened to her. Goldy finds another of these puzzles on the desk in the living room of Holly’s rented houses after she dies; both puzzles are of Hunan Province in China. After being reminded of a class Holly had taught about how to make two-sided jigsaw puzzles (with the country of Turkey on one side and the bird on the other) Goldy realizes that Holly created the puzzles to lead Father Pete or someone else to her collection of fine china, where she’d hidden a clue to be found in the event of her death pointing to Bob Rushwood as the likely killer.