[TOMT] Jewish boy takes refuge at a woman's house during WWII, she turns out to be a Nazi
I'm looking for a book I read at school 20 years ago maybe (not recent). It's about a Jewish boy fleeing during WWII who finds refuge at a woman's house. At some point, she puts on a Nazi/military uniform and leaves, revealing she was a Nazi. and say something like we are not like that or something. Does anyone know what book this is ?
"The book was commonly read in French schools, and I remember it being set during the war.