What major event took place in Mary's life while driving to the World's Fair in Seattle?

While driving to Seattle with her family, Charlie became completely swept away with the beautiful landscape in Colorado and demanded that the family pull over so she could paint the mountainside. When the family groaned that they wanted to keep moving toward Washington, Charlie pitched a fit. Soon after, she used her inheritance money to purchase a home in the Colorado mountains and uprooted her family to move there without discussion.