Post-Voldemort, the MoM is less corrupt. Kingsley is the Minister.
The Malfoys did not go to Azkaban after Book 7 because they colluded with Harry.
The Potters are distantly related to the Peverells, but so are many wizarding families.
Dumbledore could see Harry beneath the cloak because he could perform a non-verbal ‘Homenum revelio’ -
Winky is “still at Hogwarts” and fought in the last battle.
JKR: “Hermione began her post-Hogwarts career at the Department for the Regulation and Control of Magical Creatures where she was instrumental in greatly improving life for house-elves and their ilk. She then moved (despite her jibe to Scrimgeour) to the Dept. of Magical Law Enforcement where she was a progressive voice who ensured the eradication of oppressive, pro-pureblood laws."
Teddy Lupin was raised by his grandmother Andromeda Tonks, and was very close to his godfather Harry.
After Book 7, Minister Kingsley asked Harry to head up his new Auror Department.
After Book 7, “Ron joined George at Weasleys' Wizarding Wheezes, which became an enormous money-spinner.”
After Hogwarts, Ginny played professional Quidditch for the Holyhead Harpies, then became the Senior Quidditch correspondent at the Daily Prophet.
The Deathly Hallows were based on ‘the Pardoner’s Tale' by Chaucer.
JKR: “Luna became a very famous wizarding naturalist who discovered and classified many new species of animals (though, alas, she never did find a Crumple-Horned Snorkack)”
Luna married later in life to Rolf Scamander, a fellow naturalist and the grandson of Newt Scamander
“In essence divided” was Dumbledore’s theory that Nagini’s essence was divided - that it contained part of Voldemort's soul, and that was why it was so very adept at doing his bidding. This also explained why Harry, the last and unintended Horcrux, could see so clearly through the snake's eyes, just as he regularly sees through Voldemort's.
JKR: “When Dudley was attacked by the Dementors he saw himself, for the first time, as he really was. This was an extremely painful, but ultimately salutory lesson, and began the transformation in him.”
JKR: Remus was killed by Dolohov and Tonks by Bellatrix.
Wands work their best for the person the wand chooses, but will also work fairly well for a family member.
Umbridge was able to conjure a Patronus while wearing the locket Horcrux because she is so nasty.
JKR: Percy Weasley “ended up as a high-ranking official under Kingsley.”
JKR: Griphook was wrong - Gryffindor did not ‘steal’ the sword.”
Azkaban no longer uses Dementors.
“The Hufflepuff common room is accessed through a [still-life painting] near the kitchens. It is a very cosy and welcoming place, as dissimilar as possible from Snape's dungeon. Lots of yellow hangings, and fat armchairs, and little underground tunnels leading to the dormitories, all of which have perfectly round doors, like barrel tops.”
George Weasley named his first child Fred. He became very successful businessman.
Dumbledore’s vision in the Mirror of Erised was to see his family alive, whole and happy - Ariana, Percival and Kendra all returned to him, and Aberforth reconciled to him.
Jo changed her mind about someone doing magic late in life when she was writing Book 3.
Wormtail picked Voldemort’s wand up at Godric’s Hollow and saved it for him.
Tom Riddle would have turned out very different if his mother had survived and loved him.
Snape is a hero, but a “flawed” one. An anti-hero.
Regulus was able to figure out what Voldemort was doing with the Horcruxes because Voldemort arrogantly dropped hints about why he could not be killed.
Lily might have grown to love Snape “if he had not loved Dark Magic so much.”
The number of Dementors have been greatly diminished because despair and degradation have been lessened in the world.
Fawkes left Hogwarts when Dumbledore died – like Dumbledore, he could not be replaced.
Dumbledore understood Mermish, Gobbledegook and Parseltongue.
Lockhart will never recover.
Harry made sure that the Wizarding world knew that Snape was a hero and on Dumbledore’s side, though Rita Skeeter probably wrote an expose about him.
Teddy Lupin is a Metamorphagus, not a werewolf.
Socks were a running joke in the books and are not symbolic.
Horcrux murders: The diary - Moaning Myrtle; The cup - Hepzibah Smith, the previous owner; The locket - a Muggle tramp; Nagini - Bertha Jorkins; The diadem - an Albanian peasant; The ring - Tom Riddle Sr.
Dumbledore gave Ron his Deluminator because he knew Ron would need guidance.
Dementors do not have souls.
The third thing Hermione smells with Amortentia is the scent of Ron’s hair.
After Book 7, Slytherin House became more diluted and was no longer solely pureblood; however its dark reputation lingers.
Snape became a Death Eater because he was “insecure and vulnerable” and wanted to be a part of something “impressive.”
Snape thought he could have his dark magic friends and Lily too. He never understood her aversion and thought she would be impressed.
JKR: “the real Master of Death accepts that he must die, and that there are much worse things in the world of the living.”
Harry used the Cruciatus Curse because he was in an “extreme situation” and was so angry to see young children threatened. He is not a saint.
JKR: “Harry's faults are primarily anger and occasional arrogance.”
Harry’s son James probably has the Marauder’s map (but Harry didn’t give it to him).
When Petunia paused at the door as she was leaving she almost wished him luck and told him that “her loathing of his world, and of him, was born out of jealousy.” But she couldn’t do it; she had “hardened” too much.
JKR “always wondered why nobody ever asked [her] what Dumbledore's wand was made of!”
There is nothing special about Aunt Muriel’s tiara (the old bat!)
Harry lost the ability to speak Parseltongue when his scar Horcrux was destroyed.
Aberforth got Sirius’s mirror from Mundungus.
Dumbledore’s boggart is the corpse of his sister.
After Book 7, Umbridge “was arrested, interrogated and imprisoned for crimes against Muggleborns.”
Even Muggles notice that things are better with Voldemort gone; even the weather is better.
Muggles can be born with magic because it is a recessive gene; it resurfaces generations later.
After Book 7, Rita Skeeter quickly wrote a biography of Harry; she is still reporting.
Hermione was able to find her parents and undo their memory damage.
Minerva McGonagall was not in love with Albus.
JKR: “James always suspected Snape harboured deeper feelings for Lily, which was a factor in James' behaviour to Snape.”
The Chudley Cannons should abandon all hope of ever winning the Quidditch World Cup.
Regulus had a change of heart because he was not prepared for the reality of life as a Death Eater.
Voldemort’s cruelty to Kreacher was the last straw.
Draco has been sobered by his misfortune, and his son Scorpius is a much better person.
Draco and Harry never became friends, but they did come to understand and appreciate each other better.
Snape was badly groomed because it just wasn’t a priority for him.
The Resurrection Stone is now probably buried in the Forbidden Forest.
Voldemort’s curse on the DADA position at Hogwarts has been lifted.
JKR: Quirrell “was teaching at Hogwarts for more than a year, but NOT in the post of D.A.D.A. teacher. He was previously Muggle Studies professor.”
Aberforth is still at the Hog’s Head “playing with his goats.”
JKR recommends Arkie Alderton's Kwik-Repair Shop for broken flying brooms and advises us never to fix them at home.
Narcissa Malfoy was never a Death Eater even though her views were identical to her husband’s.
Arthur Weasley fixed Sirius’s motorbike; Harry has it now.
Dumbledore liked and understood Ron more than Ron knew.
Firenze survived his wounds and was welcomed back into the Centaur herd who realized that “pro-human leanings were not shameful.”
JKR’s favorite scene in Book 7 is Chapter 34: The Forest Again.
JKR: A Patronus “often mutates to take the image of the love of one's life (because they so often become the ‘happy thought’ that generates a Patronus).”
Voldemort is not a ghost; “He is forced to exist in the stunted form we witnessed in King's Cross.”
JKR: “Voldemort accidentally broke his soul into eight parts, not seven.” [Horcruxes]
There are two different memory charms. One wipes memory and one changes what you remember.
Voldemort could not stop Harry from seeing into his mind because he was “losing control.”
Viktor Krum fell in love with a woman back home in Bulgaria
Hedwig’s death “represented a loss of innocence and security” for Harry. It “marked the end of childhood.”
Both Harry and Ron will appear on Chocolate Frogs cards; this will thrill Ron who “will describe this as his finest hour.”
JKR won’t tell us what the incantation for Horcrux creation is.
Snape is the only Death Eater that could produce a Patronus because “because a Patronus is used against things that the Death Eaters generally generate, or fight alongside.” (They don’t need them.)
Nagini could see Harry and Hermione under the Invisibility Cloak because a snake’s senses are different, especially relating to heat and movement.
The other two titles JKR considered were Harry Potter and the Elder Wand and Harry Potter and the Peverell Quest.
JKR would like an otter (like Hermione’s) for a Patronus, but she thinks she’d get a big dog instead.
Voldemort never figured out that the Resurrection Stone was in the ring because he did not invoke it properly (simply wearing it wouldn’t work).
The Death Eater’s Dark Marks will eventually fade to look like a scar. They will no longer burn or hurt.
The Quibbler is back to publishing articles about the lunatic fringe “and is appreciated for its unintentional humour.”
Winky has sobered up a bit.
Bellatrix’s true love was always Voldemort, not her husband.
Snape was careful not to reveal his Patronus to other members of the order.
Voldemort never loved anything except power and himself.
JKR would like to have the same wand as Harry: holly and phoenix feather.
Members of the DA still have their coins, as they are like badges of honor (especially for Neville).
Snape got into Grimmauld Place “immediately after Dumbledore's death, before Moody put up the spells against him.”
JKR chose the lightning shape for Harry’s scar because it was a “cool” shape.
Marietta’s “SNEAK” pimples left a few scars.
JKR chose King’s Cross for Harry’s place between life and death because the name worked so well and because “Harry would associate it with moving on between two worlds.” It would look different to someone else.
JKR would choose ‘I did it my way’ by Frank Sinatra for music at Dumbledore’s funeral.