Narcissa Malfoy was good at picking up social cues. She may not have been a Death Eater (not officially anyway) but the Dark Lord knew how to use her gifts to his advantage. Multiple times, she was sent out to greet guests, assess them via Legilimency before reporting to the Dark Lord. Sometimes she didn't even need to use her magic. She was fluent in body language and her brain connected dots quicker than many could keep up with.