Heather's new novel, Defy The Night, came out recently. She finished work on it during her pregnancy. It's a continuation of the story (begun in How Huge The Night) about a family in unoccupied France early in WWII, in a town that helped many Jewish children escape the Nazis. This book focuses on the daughter and her efforts to help children in the internment camps set up in France.
It's fiction, but inspired by actual events. The story of Le Chambon-sur-Lignon can be found here.