She was barely given any time, you can't say she completely calm just because there were a few seconds where she did nothing, SevenSeven wasn't doing anything bad at that instance either does that mean he's always calm? No it doesn't.
So what's your point? that just because she's cute that she isn't deadly and or crazy, looks are nothing looks do not define who a person is. Her being cute doesn't mean a thing, she could still be deadly and crazy just like her family but we don't know what her personality is because she only had a few seconds of screen time, a few seconds where she did nothing.