Miss Wyckham was George Woods' schoolteacher, and a double agent for the Nazis.
Biography
She met George and Clyde Langer on their way to alert the Home Guard, and told them the whole village had been surrounded by Germans. She pretended to help the boys capture the Nazis in the church, but revealed that she was a double agent. She fled with Koenig and the other Nazis when George and Clyde stopped their plan to use a machine to block British radio signals and invade without being detected. (SJA: Lost in Time)