How did Mary know her relationship with her neighbors in Texas was beginning to change?

After Mary's family inherited the large sum of money when her grandmother died, Mary began to notice that the neighbors began treating her family differently. Many in the neighborhood became withdrawn from the Karr family and gossiped behind their backs. The neighbors couldn't understand why Charlie was buying expensive furs or why Pete was taking three-week vacations with his family. When the Karr's bought a mountain house, that was the breaking point. As the family pulled away in their car, the neighborhood children stood around and threw gravel at their car.