English playwright Lucinda Coxon is the woman behind the girl. The British writer has written the script for “The Danish Girl,” adapted from David Ebershoff’s novel. The film from Focus Features opened in November and widens on Christmas. Most films have a long and unpredictable road in getting to the screen, but “Danish Girl” has some unique twists. Here are five surprising facts:

1. There has only been one writer involved.
In the past 11 years, the project went through three false starts, about six directors attached and 20 drafts — but Coxon was the only writer the whole time. In 2000, Neil LaBute and Gail Mutrux optioned Ebershoff’s book “The Danish Girl,” which had recently been published by Viking, with plans for LaBute to write and direct. “This is about a marriage that becomes doomed,” he told Variety at the time. But no script was written until 2004, when Mutrux and Linda Reisman sent the novel to Coxon. She says now, “It seemed such an unusual story, because Lili was a pioneer. It was also a remarkable love story, set in a fascinating period. I loved the idea and leapt at it, and assumed everyone else would as well. I thought ‘What could go wrong?'”

2. The source book was a novel.
Ebershoff had a hard time tracking down the real-life details of Einar Wegener, who transitioned into Lili Elbe. So Ebershoff novelized it, turning wife Gerda into an American from his hometown of Pasadena, Calif. Elbe had written “Man Into Woman,” which was published in 1933; it was purportedly a memoir, containing some of her diaries. But, as Coxon says, “It’s a work of many hands. There’s a great deal of wish fulfillment, and people covering themselves legally.” Coxon met with Ebershoff to talk over the film project and started her own detective work. However, it wasn’t easy. Denmark didn’t have records; there had been medical records in Dresden’s women’s hospital, but after WWII, nothing remained. There were brief newspaper items, memoirs of the Wegeners’ friends and accounts of some surgeries in those days. Coxon added many factual details in her script, which is closer to the real events than either Elbe’s book or Ebershoff’s novel.

3. Nicole Kidman wanted to play the Eddie Redmayne role.
Kidman was sent the script in 2009, with the offer to play Gerda. But she was more interested in playing Einar/Lili. (It would have been a very different film with a woman playing the role.) Kidman was the first actor attached to the project and Tomas Alfredson (“Let the Right One In,” “Tinker Tailor Soldier Spy”) was attached to direct. But the project never got off the ground.

4. Despite the long gestation, it was a fast birth.
Casting director Nina Gold sent Coxon’s script to Tom Hooper, who loved it and was determined to film it — but only after directing the 2012 movie “Les Miserables.” Filming on “The Danish Girl” was set to begin in late 2014, but was pushed to a February, 2015 start, to accommodate the schedule of Alicia Vikander. Hooper and the film were invited to the Venice Film Festival, which ran Sept. 2-12. This meant that after 10 years, there was only seven months between the start of production and the Venice premiere.

5. It played at the White House.

On Nov. 23, the White House hosted a Champions of Change event, honoring the creatives behind “Tangerine,” “Transparent” and “The Danish Girl.” Director Hooper told Variety that it was very moving to see how much “Danish Girl” meant to the people there. “One said she never imagined that in her lifetime trans people would be accepted enough to go to the President’s home.” While a few protesters have said that a trans person should have played the lead, that’s overlooking the financial realities of the film industry. People have generally been enthused; the film has inspired more research into the period, and brought attention to Elbe and to Gerda Wegener, who will be the subject of a big art exhibition in Copenhagen. Coxon says that it’s been a long haul, but admits it would have been a very different film if it had been made 11 years ago. “It never occurred to me, even three years ago, that we would release the film in this kind of landscape. To be invited to the White House says a huge amount about how quickly events have moved.”