I see her name on the cast list but I never saw her in the movie?
I think you're getting Emma Watson (Hermione) mixed up with Emily Watson.
LOL, Don't worry, you're not the first person to get mixed up with Emma Watson (Hermione) and Emily Watson (the main actress in this). It's bit like Jennifer Beals vs Jessica Biel or Bill Paxton vs Bill Pullman
Or indeed Keith David vs David Keith.