Rita Ora

She appears in the movie Harry Potter et le prisonnier d'Azkaban (2004) in the background during the scene when Harry, Ron and Hermione attend professor Trelawney's divination class. Her character can be seen wearing a Gryffindor tie. She is not credited anywhere for this small role.

I never think too hard about a look. When you consider an outfit too much, that's when it goes wrong.