Rowling decided to respond to only three of numerous questions asked by fans. She first answered a fan's question about how the Horcrux within Harry Potter wasn't destroyed when he was bitten by the basilisk in "Chamber of Secrets".
"The Horcrux-receptacle has to be destroyed BEYOND REPAIR, so Harry would need to have DIED," she replied and added, "#pleaseneveraskmethatoneagain."
The next question is related to the fate of Hagrid's three-headed dog from "Sorcerer's Stone", Fluffy. "He was repatriated to Greece. Dumbledore liked to put Hagrid's more foolish acquisitions back where they belong - not the forest," she said.
She went on responding to another good question, this time about why 12 Grimmauld Place, Sirius Black's house and the headquarters of The Order of the Phoenix, is located in the middle of a muggle house complex. "A Black ancestor coveted the beautiful house, so 'persuaded' the Muggle occupant to leave & put the appropriate spells on it," she explained.