^IIRC it was that she sometimes visits to play chess or somesuch with Bei who is (according to Ning's bio) apparently one of the very few people around who can, and also dares, give her an even match - the downsides of cultivating a vaguely sinister Richelieu-esque rep I guess. (On the same vein Bei basically said outright that Ning's about the only person who treats her as an equal instead of with some degree of deference and awe.)