Hermione makes polyjuice potion but it fails for her and she turns into a cat. After this she is taken to the hospital wing so surely they know that she has taken it and has broken school rules – so why isnt she punished?
Because it said the ":Madame Pomfrey never asks too many questions":, and isn’t a long-lasting effect so it would have worn off anyway, without the hospital wing. Also, Madame Pomfrey didn’t know Hermione had made the potion, which is the bad thing, it’s not bad to drink it, because Hermione could have been tricked into drinking it.
Taking Polyjuice didn’t break any school rules — Hermione got the recipe out of a book she borrowed from the restricted section of the school library, using a note from Lockhart. Effectively, a teacher authorised her to make it.
The only rule-breaking she did was pinching some of the PP ingredients out of Snape’s store cupboard while Harry and Ron caused a diversion in a Potions class. But while Snape knew that stuff had gone missing (and could guess what it had been used for), and assumed that Harry &: co. had stolen it (in GoF, he accuses Harry of breaking into his cupboard for a second time), he could not prove it.
Besides which, for Hermione to spend several weeks in the hospital wing looking like a catgirl — and missing her lessons! — was probably considered ‘punishment’ enough by the rest of the staff.
Hermione did go to the Hospital Wing, Harry and Ron had to convince her that she had to, they said Madame Pomfrey wouldn’t ask too many questions. Remember that a lot of things must happen to students at Hogwarts from accidents and experiments etc, and like real hospital sometimes the doctors or nurses (or matron in this case) have to not ask in order to treat the patient. She probably had an idea what Hermione had done though.
I don’t think its explained thoroughly, I mean in the film she end up petrified like 1 or 2 scenes later, not a (cat) hair on her body.
She didn’t go to hospital when she turned into a cat ( she stayed in the restroom until Ron and Harry were done). It was when she got petrified that she went to hospital.
Madam Pomphrey doesn’t ask many questions about how injuries happen.
I don’t think he went to the hospital wing I think she just hid until it wore off!
She never leaves the restroom.