Fiona Shaw as Petunia Dursley
Vernon and Petunia Dursley are the horrible distant relatives that Harry was forced to live with after losing his parents on that one fateful Halloween night. OK, maybe not so distant. While being the sister of Lily Potter, Petunia Dursley could not be more different from her sister. It seems that while Lily was a kind-hearted witch, her sister, Petunia, was a self-centered muggle who had little to no interest in the Wizarding World, and even less so towards her reluctantly adopted son, Harry.
Although Petunia does at least agree to take care of The Boy Who Lived after Lily and James Potter pass away, she spends most of her time using him for her various house chores, and as a punching bag for her spoiled son, Dudley.
Kelly Macdonald as Helena Ravenclaw
Yes, you're not hallucinating. We already saw The Grey Lady/Helena Ravenclaw on this list but summed up the fact that the old Helena never played it past Harry Potter and the Sorcerer's Stone. Kelly Macdonald, brought the character back to death (because she's a ghost) for the returning appearance of The Gray Lady in The Deathly Hallows: Part 2.
Although it's not exactly what she had planned, Helena Ravenclaw helped Harry take down the Dark Lord, by revealing the history behind the ‘lost Diadem' that she had taken from her mother when she ran away from home. The same Diadem that Voldemort had turned into a Horcrux.
Kelly Macdonald Now
It's fair to say that Kelly Macdonald's appearance in Harry Potter and the Deathly Hallows was not exactly the largest role ever. That being said, she did manage to use the, albeit small, platform given to her by the franchise in order to showcase her acting talents and make a name for herself. Since her time on the Harry Potter set, Kelly has landed roles in some major Hollywood movies.
In recent years, she starred as the nanny in Goodbye Christopher Robin, and appeared in No Country for Old Men and Holmes and Watson, along with another Harry Potter cast member - Pam Ferris.
Fiona Shaw Now
You'll be glad to know that, in real-life, Fiona Shaw is nothing like the irritating, selfish character that she plays in the Harry Potter movies. She does, however, seem to have a love and strange affinity for all things fictional and supernatural. Having trained in the Royal Academy of Dramatic Arts, Shaw began her career in the theater, and only later moved up to TV and film.
Since her time on the franchise, Fiona has starred in a number of magically fantastical movies and TV shows. You may have seen her playing Marnie Stonebrook on the hit show, True Blood, on Dorian Grey, or most recently, on the British television series, Killing Eve.
Kate Fleetwood as Mary Cattermole
Mary Cattermole (back row in the middle) is the wife of Reginald Cattermole, whom Ron disguises himself as when he drinks the Polyjuice and breaks into the Ministry of Magic with Harry and Hermione. As a Muggle-born, Mary is accused of stealing a wand, and was forced to attend a Ministry hearing, where she is interrogated by the abominable Mrs. Umbridge.
She would have been sent Azkaban too if it wasn't for Harry and the gang disguising themselves as Ministry workers, interfering with the trial, and freeing Mary and the other Muggle-borns to warn them to get out of the country before He-Who-Must-Not-Be-Named attacked.