A Texas judge has ordered the publisher of EL James’s bestselling trilogy Fifty Shades of Grey to pay $11.5m to a Fort Worth elementary schoolteacher who the court ruled was defrauded of her share of royalties.

Jennifer Pedroza of Arlington, Texas, filed suit in May 2014 against her former business partner, Amanda Hayward. The two worked for the Writer’s Coffee Shop, the e-publishing company that first published the erotic novels that would go on to become bestsellers.

In the lawsuit, Pedroza accused Hayward of “greed and self-dealing” by “conning” her business partner and other women involved in the early days of the Writer’s Coffee Shop. The novel made the business at least $40m, according to court documents.

Pedroza’s attorney, Mike Ferris, said they were happy the judgment had been signed and that his client had felt “vindicated” by the jury’s verdict.

“We also realize it’s not over yet,” Ferris told the Guardian.

Hayward lives in the Sydney suburb of Dural and is CEO of the Writer’s Coffee Shop. Her attorney, David Keltner, told the Fort Worth Star-Telegram that they are preparing an appeal, which could delay or stop Pedroza from receiving the payout. “We do not believe Texas law justifies a partnership by conduct on these facts,” Keltner said.

But Ferris noted: “I would rather be the party with the judgment in my favor.”

Texas state district judge Susan McCoy determined the award after an audit of the company’s finances. McCoy also ordered Hayward to pay $1.7m in attorney’s fees.

McCoy concluded that Pedroza had been defrauded of royalties after a four-day trial in February 2015. Then, she ordered Hayward to set aside more than $10m in anticipation of the final decision, which was announced on Thursday.

The Fifty Shades series topped bestseller lists internationally and the film adaption broke box office records. The first book in the three-part series was the UK’s fastest-selling paperback book ever.

It was first published on The Writer’s Coffee Shop, an online blog that began in 2009 as a space for people to write fan fiction and discuss books.

The Writer’s Coffee Shop became an Australian-based independent publisher in October 2010. The next year, it published Fifty Shades of Grey as an e-book and print-on-demand book. It went on to sell 250,000 copies, a huge number for an e-book. In 2012, Random House made a deal with the company to publish the books.

Random House is not named in the lawsuit, which claimed that Hayward had secretly turned the site into a company she owned exclusively.

Christa Beebe of Arlington filed the suit with Pedroza. She had done marketing and distribution work for the Writer’s Coffee Shop. Beebe settled her suit in December 2014.

Hayward and Pedroza never signed a partnership agreement, though Pedroza was named in a partnership income tax return.

Pedroza said in a statement: “My family and I feel relieved and vindicated with the outcome of the trial and the judgment signed today.”