1. Picking the wrong wand to use when in a hurry and finding she's got the one that requires pumpkins as a key ingredient.
2. Discovering she's got the wrong translation spell in her wand and slippers end up being made out of glass for some reason.
3. Discovering the spells that mean she has to use animals and transform them into something else bring her out in a nasty rash. (Of course that could just be an allergy to the animals' fur).
4. Really wanting to zap someone but knowing she's supposed to be nice so must show restraint.
5. Knowing she's expected to look older, wise and friendly when she really wants to put on something much more daring and hit the town.