The collection of fairy tales, which is a companion piece to Rowling's wildly popular "Harry Potter" books, went on sale Dec. 4.
"All royalties will be going to help children without families, many of them with disabilities, whose voices have been unheard for many years," the BBC quoted Rowling as saying. "I am absolutely delighted that so much money has been raised. I would like to thank everyone who has so far purchased a copy of the book."
Proceeds of the book go to benefit the Children's High Level Group, a charity Rowling co-founded to help vulnerable children in Central and Eastern Europe, the BBC said.
The book reportedly is on track to be the year's No. 1 seller in the United Kingdom.