Ask her!! Have her make you a list of things she would consider rewards and things she would consider punishments, have her rank them in terms of severity for her. Personally I hate housework, so if I've been snippy with Master, He lets me know I've displeased him and how he expects me to behave and in order to get back in his good graces I have to do something for Him He knows I find unpleasant.
Making a list of punishments wasn't the easiest thing for me and was used as a punishment in its self.