The number one rule of behavior: People will do what they perceive is their best option. If she is being disobedient, it is because she thinks she will get more benefit out of it than being obedient. It could be that she enjoys the 'punishment', she could enjoy the rush of being in 'trouble', it could be what you are paranoid about. Until you understand her motivation, you will be shooting in the dark when you try to change her behavior. Your best bet is to talk with her about this.

As an aside; punishment based dynamics make great fantasy, but poor reality. In side by side comparisons, the carrot almost always outperforms the stick in generating long last compliance. The times when punishment is your best choice are few and far between.