Author J.K. Rowling says she's done with the story of Harry Potter, buts he won't rule out another tale set within the same universe.

The British author, who is the first ever to become a billionaire as a novelist, said that while "where Harry's story is concerned, I'm done," she would possibly consider revisiting the magical world she created for a future novel.

"I don't want to go mechanically back into that world and pick up a load of odds and ends and glue them together and say, 'Here we go, we can sell this,'" Rowling said Wednesday. "It would make a mockery of what those books were to me. But ... if I did have a great idea for something else, I probably would do it."

Rowling wouldn't say much else about what form that "something else" could take, except that it likely won't be a bit of Harry Potter's life that takes place before or after her famous seven-novel series.

"I am very averse to the prequel-sequel idea. A sidestep could maybe ... well, we'll see," she said.

The author also revealed that there are a few "Potter" novels that she thinks could have been better if she had had more time to work through them.

"There were a couple of the Potters and I definitely knew that they needed another year," she said."I had to write on the run and there were times when it was really tough. And I read them, and I think 'Oh God, maybe I'll go back and do a director's cut.' I don't know."

Rowling is promoting her new novel, "The Casual Vacancy," which is directed at adults and will hit book stores on Thursday, Sept. 27. The book contains content that wouldn't be suitable for the age group that "Harry Potter" targeted, she said.

"I hope that we've made it really clear that this isn't a book for children," Rowling said.

But she added that the massive success of "Harry Potter" freed her financially and gave her the ability to explore herself as an author without having to depend on her work for a paycheck.

"'Harry Potter' truly liberated me in the sense that there's only one reason to write, for me - if I genuinely have something I want to say, and I want to publish it," she said.