Aunt Petunia Dursley
Background
Petunia Dursely is a resident of 4 Privet Drive, Little Whinging, Surrey. She is married to Uncle Vernon Dursley and her son is Dudley Dursley. Petunia's nephew is Harry Potter, who she adopted. Her sister was Lily Potter and her brother in law was James Potter.
During the events of Harry Potter and the Sorcerer's Stone (2001) played by Fiona Shaw
Aunt Petunia bangs on the door of the cupboard under the stairs where Harry is kept and tells him to wake up. Dudley runs down the stairs but stops to repeatedly jump up and down on the stairs above where Harry is kept. Harry walks into the kitchen and Aunt Petunia tells Harry to cook breakfast without burning anything. Dudley counts his birthday presents and starts yelling when he notices there is one less than the year before. At the zoo, Dudley sees the Burmese python moving and shoves Harry aside and Harry makes the glass disappear. Dudley falls into the snake exhibit and the Burmese python tells Harry thanks as it slithers away. A Hogwarts owl drops off a piece of mail addressed to Harry. Dudley sees Harry looking at his letter and takes it from him and gives it to Uncle Vernon who keeps it when he notices it is from Hogwarts. Day after day, more letters arrive from Hogwarts, which Uncle Vernon continues to rip up or burn. On Sunday, the Dursley house is flooded with letters from Hogwarts and Uncle Vernon decides they are going to leave. They go to a remote shack to live and on Harry's 11th birthday, Hagrid shows up and gives Harry a birthday cake. Hagrid introduces himself to Harry and tells Harry he is a wizard, before handing Harry his acceptance letter from Hogwarts. Uncle Vernon tells Hagrid, Harry will not be going to Hogwarts and Aunt Petunia insults Harry's mother. Uncle Vernon insults Albus Dumbledore and Hagrid makes Dudley grow a pig tail when he sees Dudley eating Harry's birthday cake. Hagrid and Harry then leave and go to London.
During the events of Harry Potter and the Chamber of Secrets (2002) played by Fiona Shaw
When Harry walks downstairs, Aunt Petunia, who is finishing a cake, tells Harry, Uncle Vernon is in the living room. After dinner, Harry slowly follows the cake Aunt Petunia made with his arms outstretched to try and grab it as it travels towards Mrs Mason. The cake falls on Mrs. Mason's head, covering her in cake.
During the events of Harry Potter and the Prisoner of Azkaban (2004) played by Fiona Shaw
Aunt Marge walks in and hands her dog off to Aunt Petunia. Aunt Marge gets upset with the way Harry talks to her and calls him ungrateful. During dinner, Aunt Marge sees Harry staring at her and she asks him if the school he goes to canes him for misbehavior, she asks Aunt Petunia about Harry's parents and calls James Potter a drunk. Harry angrily denies it and the glass in Aunt Marge's hand shatters. Aunt Marge then says it wasn't James' fault for how Harry turned out and says "if there is something wrong with the bitch, then there's something wrong with the pup". Harry yells at her to shut up and suddenly Aunt Marge starts to expand to great proportions. She floats into the air and eventually floats out of the house.
During the events of Harry Potter and the Order of the Phoenix (2007) played by Fiona Shaw
Aunt Petunia is watching the news where TV Weatherman is talking about how hot the weather is. She sees Dudley, who is in a daze and tells Uncle Vernon to come over. Uncle Vernon asks Dudley who did it to him, and Dudley points at Harry. A letter from the Ministry of Magic arrives and Mafalda Hopkirk's voice rings out and she accuses Harry of breaking the Decree for the Reasonable Restriction of Underage Sorcery and therefore, he is expelled from Hogwarts. Uncle Vernon and Aunt Petunia then take Dudley to the hospital.