Just follow her questline. Catch her sleeping in class, punish her in your office. Level her up to the point when you can assign role as after-punishment action.
Depends on which level you are stuck on. Hard to tell from your description, but assuming it is from L2 to L3. For that, you need to have bought the paddle and the ointment. You also need the action 'massage inner thigh' which you get when advancing both Ms Newman and Debbie's questline; if Pleasure is the issue, it sounds like this is the action you are missing.