Faith, Hope, and Ivy June by Phyllis Reynolds Naylor

Two girls in 7th grade participate in a two week exchange program in Tennesee. One girl is from a mining community and lives without electricity or indoor plumbing, the other from Lexington, attends private school and has four bathrooms in her house. The girls explore how thier lives are different and discover some surprising ways in which they are similar. Sometimes it's not easy to keep your word.