Rowling brought proceedings against Russells law firm partner Chris Gossage, and his friend Judith Callegari, who tweeted the information. Callegari deleted the tweet shortly thereafter.
Russells contacted Rowling's agent, saying that Gossage spilled the beans to Callegari.
Rowling was not in court for the hearing, but has now accepted a charity donation from the law firm to the U.K. Soldiers' Charity. The firm will also reimburse all of Rowling's legal costs.
"I always intended to give The Soldiers' Charity a donation out of Robert's royalties," Rowling said. "But I had not anticipated him making the bestseller list a mere three months after publication -- indeed, I had not counted on him ever being there!"