Infer how liesel knows the mayors wife saw her take the book from the bonfire

Liesel sees three books that remain mostly intact and she steals a blue book called The Shoulder Shrug. She puts it under her shirt even though it is still hot. Although she was ignored by the workmen, Liesel realizes that one person saw her steal the book: the mayor's wife, Frau Hermann.THe Mayor's wife eventually leaves her husband's library door open for Liesel to take books.

When Liesel decided to take one of the books from the shelf, she saw that the Mer's wife noticed this. Later, she was ashamed, but oddly enough, the Mer's wife did not give her away, but left the door to the library open so that Liesel could dig other books. It reminded me of essays on illegal immigration to the United States and our days. Now at the border they may also not notice the intentions of illegal migration and allow people with a tourist visa to pass. At least I experienced such deja vu while reading this story.