az- Searching for Shona --by Margaret J. Anderson:
Card Catalog Description: During the evacuation of children from Edinburgh in the early days of World War II, shy, wealthy Margaret on her way to relatives in Canada trades places and identities with the orphaned Shona bound for the Scottish countryside.

-It's the early years of WWII, and the Nazi war machine is about to unleash its fury on England. In order to protect their children from harm, thousands of Londoners are sending their children to the country or, if they can afford it, out of England entirely. Two orphan girls meet in a embarkation area. One girl is from an affluent family and is being sent to Canada; the other, who is from a working class background, is being sent to the country. They are both the same age, look similar to each other, and have no parents. The rich girl decides that she doesn't want to go to Canada, and strikes a deal with the poor girl to switch clothes, destinations, and identities for the duration of the war. Of course, neither of them know that the war will last for six years.The rich girl assumes the life of her poorer counterpart, and discovers a world very different from that of her own upbringing. The war ends, and she is a completely different person than she was six years earlier. Will she go back to her former life of privilege and wealth?

-Like a previous reviewer, I also read this book over 20 years ago, but the story stuck with me. As a matter of fact, it took quite some time to actually remember the name of it so that I could purchase it for my own daughter! The suspense and plot twist at the end made this an unforgettable book for any young adult.