What was the name of the blonde that came to dinner with the fury the boy in striped pajamas?

In "The Boy in the Striped Pajamas," the blonde girl who comes to dinner with Bruno's family is named Gretel. She is Bruno's older sister and is depicted as being influenced by Nazi ideology, contrasting with Bruno's innocence and curiOSity about the world around him. Her character represents the indoctrination of youth during that era.