What I hate is when certain people like her daughter or that girl who played Pocahontas in that movie The New World(or anyone who was on tv or a movie just once) get all kinds of praise before I even get an ounce of constructive criticism.
You have celebrities in your class or at least people who are in movies? You must be in LA.
Her praise for them makes perfect sense though. If one of these students is in movies that require martial arts or somehow becomes a big star she is suddenly going to become a trainer to the stars and will be able to work with big names for big money. Maybe she wants to get into choreographing fights or something too so she wants those connections. Treating them special seems like an obvious career move.
It wasn't always like that either, I remember when she clearly started to turn into a devil.
In a situation like this I think the daughter comes to mind as a possible cause. Both if she likes you or doesn't like you could get her mom pissed at you. Not only that but you say that you are better than her. Did you show up her daughter sometime that would piss her off?