Remember that bit in "Harry Potter and the Half Blood Prince", where Harry and Dumbledore are meeting in a cafe, and Harry gets a little awestruck by the waitress? That's Elarica Johnson. She didn't have a major role in the films, but she made just as big an impression on some viewers as she did on Harry.
Johnson also sometimes works under the name "Elarica Gallacher", and is still pushing to get her TV career started. One of her bigger recent successes was landing a part in "Strike", which is based on J.K Rowling's novel "Cuckoo's Calling". We'd like to believe that J.K. herself made that casting decision. She's also appeared on long running British soap opera "Eastenders", but she may be just as well known for her smoldering hot Instagram account, which shows that she spends a lot of time on vacation and looking fabulous.