"I absolutely love writing for children, so I'm certainly not closing that door. I would love to do more," she said. "It's always been for me: When the idea finds me, I'll do it."

Rowling said she was also finishing the third book in her series written under the pen name Robert Galbraith. She was unmasked as the author after the first book came out, and said she worried briefly when that happened that another book would be somehow less enjoyable to write.

"I thought 'This has blown it. It won't be as much fun anymore.' But actually it is," she said. "I'm maintaining Robert. Robert is quite real to me as an entity, so I like that. I know it's pretense. I know it's make-believe, but it helps me to slip into that persona."