The character of Katie takes us all by surprise in Harry Potter. She's just sort of there in the background most of the time, never really making a huge impression, and then she almost dies in "Harry Potter and the Half Blood Prince", nearly breaking our hearts in the process.
Georgina Leonidas does a great job of playing the role, particularly in that film, and someone must have noticed because she's currently a regular performer on the stage in London theaters, which are notoriously reserved for more "serious" actors. She's good friends with Jessie Cave from their Harry Potter days, and the two have been known to make the occasional YouTube video together. If you check her out on Instagram you'll find her all grown up with tattoos and attitude - and plenty of pictures of her dog, too!