"Don't tell me the soldiers try to—what's the word?—relocate butter, too?" She laughed at her own joke.
But it wasn't a joke at all, though Mama laughed ruefully. "They do," she said. "They relocate all the farmers' butter, right into the stomach of their army! I suppose that if they knew Henrik had kept this tiny bit, they would come with guns and march it away, down the path!" (8.11-12)
To someone who knows the terrible fate of many of the relocated people (we readers know that, sadly, many Jews died at the Nazis' hands), this type of joke might seem terribly cruel. But to Annemarie and her mom, it's just an expression of how much control the Nazis have over their lives.