If I could change only 1 thing about the Harry Potter series, it would be that Harry's aunt Petunia was a magical witch and not a Muggle, who’d willingly take in Harry after Lord Voldemort murdered both his parents Lily and James Potter. Harry would at last have a loving family member he always deserved; Petunia would actually care for him exceptionally well and treat him as if he were her own birth child! Harry would at least have a mother figure should Sirius Black still be killed by Bellatrix Lestrange, thus leaving Harry without a father figure.
Also, MY story about Petunia is that she attended Hogwarts and would be sorted into Ravenclaw House and would be even more academically-talented than her sister Lily Potter, especially in Potions, but she would be very rule-abiding. For example, she also sends Harry a Howler regarding the theft of the Flying Ford Anglia, as Molly Weasley sent one to Ron. After her final year at Hogwarts, she lives a Muggle life still at 4 Privet Drive (but without Vernon Dursley since she would never have even met him, just her and Harry alone) as a best-selling author who writes stories to inspire future generations. She still fakes the story of his parents' death of them "dying in a car crash" and hides the truth that he Harry is indeed a wizard, until he receives the Hogwarts acceptance letter—but only to SPARE him a painful memory of his parents' murder. Petunia would also have fought in the Battle at the Department of Mysteries at the Ministry of Magic alongside the Order of the Phoenix members and the Battle of Hogwarts during the Second Wizarding War, constantly casting Shield Charms between the good and evil, and survive.
