Nora Ephron died in 2012, at the age of 71, but she left an indelible mark on the world as one of the most influential voices of our time. She left behind a strong legacy and continues to inspire new and emerging artists. So, it is no surprise that entertainment journalist Erin Carlson has chosen to write her first book about the late Hollywood powerhouse. In “I’ll Have What She’s Having” she takes readers behind the scenes of the writer-director’s three most successful movies: “When Harry Met Sally,” “Sleepless in Seattle,” and “You’ve Got Mail.”

I spoke to Carlson about her research process and findings from authoring this book, what she learned about women in Hollywood, Ephron’s impact on the film industry, and more.

W&H: Nora directed her first movie, “This is My Life,” at 50 years old, and the rest is history. How would you describe her impact on the film industry, and rom-coms specifically?

EC: Nora’s gifts as a writer and journalist helped make her as iconic in the romantic comedy genre as her biggest stars and creative collaborators, Tom Hanks and Meg Ryan. When Nora directed her own scripts, she was masterful — only she could envision and execute the words and dialogue she wrote and the characters whom she developed. Like any singular artist, she leaves an unmistakable imprint on her work; her sweet and tart voice courses throughout her finest films, which also happened to be her romantic comedies. And she was born to make them.

As the daughter of screenwriter duo Henry and Phoebe Ephron, who raised their four girls in Beverly Hills and specialized in romances, Nora witnessed firsthand the process of writing movies, and bringing them to the big screen. She despised the word “art.” Because she understood that filmmaking was a craft, and with more experience, something at which she could improve. The truth is male directors get more chances than their women counterparts to fail and then score another plum project.

Since her critically acclaimed debut film, “This Is My Life,” did poorly at the box office, TriStar, the studio behind “Sleepless in Seattle,” was initially skeptical about handing this novice the reins of a big-budget romantic comedy — of course, she proved everyone wrong, and that romantic comedy became one of the top-grossing offerings of 1993.

Nora knew that two things contributed to a successful romcom: writing and casting. And hers were wry, knowing, and urbane, yet drenched in the unabashed optimism of the Golden Age classics of her youth. She created strong woman characters who could stand up to the men in their lives, and show them a thing or two. For example, Sally turning the tables on Harry, and acting out a fake orgasm in a deli in “When Harry Met Sally.”

Nora truly believed in the possibility of love between equals, and it was important to her to infuse Sally Albright, Annie Reed, and Kathleen Kelly with a voice — and jokes — as strong as the male lead’s. Why should the guys have all the fun? Nora created worlds in which anything, and everything was possible — worlds that we all still want to live in, and we return to again and again.

W&H: How did you come to land on the three films that you chose to highlight from her career?

EC: “When Harry Met Sally,” “Sleepless in Seattle,” and “You’ve Got Mail” are a trilogy of romantic comedies that represent Nora’s best and most enduring work, and through which her muse, Meg Ryan, played an instrumental part. These movies are her legacy, with “Julie & Julia” runner-up — because Meryl, Stanley Tucci … butter!

W&H:You did a great deal of interviews for this book. Which women in her life did you know that you had to talk to and were there any women who did not want to speak to you?

EC: I knew that I absolutely had to speak with Delia Ephron, Nora’s sister and collaborator who worked with her on “Sleepless” and “You’ve Got Mail.” Delia told me she was the “guardian” of the sisters’ scripts, namely that Nora trusted her to protect the integrity of their screenplays during the filmmaking process. Delia had crucial insight into Nora’s vision and working style. I was lucky to interview her.

Meg Ryan, meanwhile, proved a challenge — just when I thought her publicist would connect me for an interview, she went radio silent even though Tom Hanks, her beloved colleague, had spoken with me. At the time, “Star” magazine had done a series of unflattering covers of Meg, and it appeared that she felt burned by the media and potentially even talking to journalists. Who can blame her? However, rather than Meg give me PR-approved soundbites about her own legacy in romantic comedy, it was more fascinating to put together a portrait of her based on my wide-ranging interviews with the folks who could speak openly and honestly about her transformation from ingenue to leading lady in the span of “When Harry Met Sally” to “Sleepless.”

W&H: I loved reading about Nora’s relationships with different men in Hollywood during the course of her career. Can you talk about these relationships, and particularly any sexism in the film industry that she faced during the course of her career?

EC: Nora was married three times. Her first husband was the comedy writer Dan Greenburg, whom she divorced amid the feminist movement that shook things up in the 1970s; her second was Carl Bernstein, who, together with Bob Woodward, linked Watergate to President Nixon. Bernstein left her for another woman while she was pregnant with their second child.

That experience traumatized and humiliated her — but she had the last laugh when she wrote the juicy novel “Heartburn,” a thinly veiled account of the demise of her marriage to Bernstein. That book, of course, became the movie with Meryl Streep and Jack Nicholson; Bernstein did not want this movie to get made, though he reportedly loved that Jack, the hottest movie star of his day, was playing a fictional version of Carl.

Several years later, Nora married Nick Pileggi, her third — and best — husband. Pileggi is a “famously nice guy,” as Nora has written, and renowned for his reporting on the Mafia. He wrote the book which inspired Martin Scorsese’s “Goodfellas.” More importantly, he adored Nora and relished in her success, rather than harbor resentment toward it.

But you’re asking me about Nora’s relationships with men in Hollywood! Well, she and “When Harry Met Sally” director Rob Reiner were pretty tight. He trusted her and believed in her talent and gave her the credit of associate producer on his movie; even though he had a hand in co-writing the script for Harry and Sally, Nora received the sole credit as the screenwriter, as well as the only Oscar nomination for anyone involved with the film. That says a lot about Rob. He’s a mensch, with a strong mother.

Rob appreciated Nora and her contributions and what she brought to the character of Sally as well as her keen social observations and killer one-liners. They understood each other as comic writers and as the children of parents who were successful in showbiz. With Nora, Rob saw an equal. It is utterly mystifying to me that he still believes that men and women’t can’t be friends — how, then, could Nora continue to work in Hollywood and be friends with men like Rob, or Mike Nichols, or Tom Hanks? That is the great irony.

W&H: What did you learn about women’s roles in Hollywood while writing this book?

EC: It’s still a man’s world, with shitty roles for women and a dearth of directing opportunities. Like Nora, if women want to create movies and TV series centered on female characters, then they will need to write and direct material they originate and cultivate themselves.

W&H: Which modern women in Hollywood have been greatly influenced by Nora?

EC: Funny you ask: Since Lena Dunham was mentored by Nora, and is a hugely talented writer-director in her own right, people want to categorize Lena as the new Nora. She’s not. Lena is open and unfiltered where Nora was self-possessed, always aware of the boundaries between people.

If I had to choose a Nora heir, it would have to be Tina Fey. Tina led “Saturday Night Live” for years before “30 Rock,” and the two women share a similar arch, self-deprecating sense of humor and B.S. detector that have won them zillions of female fans. Plus, they set their movies and TV shows in New York, capturing the endless idiosyncrasies of the Greatest City in the World.

Another thing: I know it sounds weird, but Taylor Swift also reminds me of Nora. She just keeps bouncing back from shit, and reinventing herself, and writing about her love life and exes within a narrative in which Taylor always wins as the heroine, never the victim, of her own story. Her own romantic comedy. Harry Styles be damned!

W&H: How far have women come since then and how do you think Nora would feel about where women in Hollywood are today?

EC: Following a summer in which Patty Jenkins’ “Wonder Woman” kicked ass, and Nicole Kidman and Elisabeth Moss cleaned up at the Emmys, it’s easy to feel better about the state of women in Hollywood today. However, we have a long way to go toward creating roles for actresses that are as compelling as those men get to play — and not just love interests, mothers, wives, and daughters.

Nora, a barrier-breaking feminist, loathed panels on women in film. She hated labels and felt trapped by them and wanted to be known as a “director,” not a “woman director.” That said, she would doubtless be heartened by a newly energized feminist movement of women and girls who are taking less shit and taking more names. “Go out and get what you want,” she might tell them. “Just do it.”

“I’ll Have What She’s Having” is available now and can be purchased on Amazon.