That old teacher just leaves the students to the gestapo?

The Gestapo was after her, not the kids. I found fascinating the debate between the kids re: whether Paris or Vichy was the capital of France. Then when push came to shove, they all united behind France.

She knew they would not be harmed, they were after Joan and it was paramount that she get this innocent girl (who had no idea that she had been followed or even that she was helping a Paris spy) out of harm's way ASAP.