Harry Potter married Ginny Weasley. They had three children, James Sirius, Albus Severus, and Lily Luna. He became head of the Auror’s Department under Kingsley Shacklebolt.
Ginny Weasley played quidditch for the Holyhead Harpies. After deciding to raise a family, she retired and became Senior Quidditch correspondent at the Daily Prophet.
Hermione Granger married to Ron Weasely and had two children, Rose and Hugo. Hermione went back to Hogwarts and sat her NEWTS before working for Department for the Regulation and Control of Magical Creatures and helping house elves. She then moved to the Department of Magical Law Enforcement where she eradicated pro-pureblood laws.
Ron Weasley went to work with George at Weasleys’ Wizard Wheezes until he became an Auror for the ministry.
George Weasley married Angelina Johnson and turned Weasleys’ Wizard Wheezes into a lucritive business. They had two children, Fred and Roxanne.
Bill and Fleur Weasley have three kids, Victoire, Dominique and Louis. Victoire seems to have a romantic interest in Harry’s godson, Teddy. She was named after the victory at Hogwarts, since her birthday shared its anniversary.
Charlie Weasley stayed single and continued working with his dragons.
Percy Weasley married a woman named Audrey. They had two daughters, Molly and Lucy.
Arthur Weasley went on as Head of the Office for the Detection and Confiscation of Counterfeit Defensive Spells and Protective Objects.
Albus Dumbledore had fallen in love with Grindelwald at one point when he was younger. He felt he had lost track of his morals while with Grindelwald, so after this he led a celibate and scholarly life.
Dudley Dursley went on to be married and have children. Harry occasionally went to visit with him, but did not maintain a relationship with the other Dursleys.
Rubeus Hagrid continued to work at Hogwarts and would have young Albus Potter to his hut to tea.
Neville Longbottom married Hannah Abbott. He went on to be the Herbolgy professor for Hogwarts.
Hannah Abbott ran the Leaky Cauldron.
Luna Lovegood married Rolf Scamander much later than Harry, Ron, Hermione and Ginny married. They had twin sons Lorcan and Lysander. She became a famous naturalist.
Firenze was allowed back into the herd.
Dolores Umbridge was arrested, interrogated and imprisoned for crimes against muggleborns.
Rita Skeeter kept writing. When asked about what happened to her, JK Rowling laughed and said she probably wrote a book about Harry after he defeated Voldemort.
Severus Snape ’s portrait was not put in the headmaster’s office at Hogwarts because he resigned before he died. But Harry told everyone of Snape’s innocence.
The Defence Against The Dark Arts job is no longer jinxed. When Voldemort was killed, the jinx lifted and the school can now keep a D.A.D.A teacher for more than a year.
Draco Malfoy married Astoria Greengrass (younger sister of Daphne) and had a son named Scorpius Cho Chang married an unnamed muggle.
Mr. and Mrs. Longbottom (Neville’s parents) never got to leave St. Mungo’s. When asked about them, J.K. Rowling said “The damage is done.”
Hogwarts is led by an an entirely new Headmaster (McGonagall was getting a little old).
J.K. Rowling lives wealthy ever after. “I’m dealing with a level of obsession in some of my fans that will not rest until they know the middle names of Harry’s great-great-grandparents,” she said in an interiew. But she also said “I love it. I’m all for that.”