Maybe your mother-in-law was out sick that day, or was someplace where they weren't doing that, but it was being done. And she would have been doing it whether or not she was "so inclined."
Gumlegs: Oh, no doubt that the Japanese government wanted to make children attack American troops. My mother (not an in-law) and her peers decided, after years of listening to government lies about Japan "winning the war," that they would not participate in such wrongdoing. I didn't say it didn't happen; I simply said there were Japanese citizens who vehemently opposed the notion.
Would they have been arrested, detained, perhaps even killed by their government? Most certainly. Did they choose to make a principled stand against a policy they thought was wrong? Most certainly.