By anyone's measure Margot Robbie is a busy woman. The box office hit The Wolf of Wall Street, in which she co-starred with Leonardo DiCaprio, may have been her breakthrough role, but she followed it up in quick succession with Z for Zachariah and Focus.

From those three films alone she's got about three quarters of a billion dollars in box office to her name.That's before we even get to this year's haul: the Tina Fey comedy Whiskey Tango Foxtrot, The Legend of Tarzan, in which she plays Tarzan's iconic mate Jane, and the highly anticipated Warner Bros-DC Comics blockbuster Suicide Squad, in which she will play the mischievous but sinister Harley Quinn.

From those, if the stars align, there might be close to a billion more coming. A weaker woman might be exhausted by the workload. But the 25-year-old former Neighbours star lopes into our interview with the boundless enthusiasm of a kid on her first day of high school. She's talkative, quick to laugh and very self-deprecating. A lot has changed since she resided in Neighbours' fictional Erinsborough.

"It is a bit busy," she says, laughing, and then becoming serious for a moment. "I would say it's very busy, but it's been really fun. No matter what country we're in or beautiful place we're seeing doing these press tours, I just want to be back on the set." Robbie has been dividing her time between filming Whiskey Tango Foxtrot, based on the battlefield memoir of journalist Kim Barker, The Taliban Shuffle: Strange Days in Afghanistan and Pakistan, and completing press tours to promote her other films.

"It's just bizarre, busy and really cool but you've got to take it all with a grain of salt otherwise you just make yourself mad," she says. We're sitting in a cool corner of the sound stages where Whiskey Tango Foxtrot is being filmed. Outside, the Santa Fe, New Mexico, sun is scorching the sandy landscape with the kind of pulsing warmth which is lovely, but only for a moment.

It's a perfect location – the film is set in Afghanistan and Pakistan – but the indoors offer a welcome respite from the sun, and a safe haven for Robbie's almost flawless pale skin. Whiskey Tango Foxtrot – or WTF, get it? – tells the story of a group of reporters covering the Afghan battlefield at a time when the world's focus shifts from that location to Iraq. Their war is obviously far from over, but to some extent they are set adrift by the media cycle, a lesser priority for the global news networks which sent them there that the more urgent, and more newsworthy, conflicts springing up elsewhere.

Tina Fey, best known as one half of the brilliant Fey-Poehler Golden Globes hosting combo and the star of the television comedy 30 Rock, plays Kim Barker, the character based on the real-life author of the book on which the film is based. Robbie plays journalist Tanya Vanderpoel. The film also stars Martin Freeman, as photographer Iain MacKelpie, and Billy Bob Thornton, as an American Marines commander.

The story, Robbie says, is very female driven, and not just because of Barker's authorship of the book and Fey's leading role in the film, as well as an off-screen role as producer. "The protagonist of the story is female obviously, I play her best friend so we've got that friendship at the heart of it," she says. Robbie's character Tanya Vanderpoel is ambitious, wanted to go to Iraq, but was forced to accept Afghanistan as a second choice.

"She's a reporter, the same as Tina's character, although she's gotten there a little earlier." she says. "She's not exactly her mentor but since she was there early she kind of takes Tina's character, Kim, under her wing and shows her the ropes."

There is also, Robbie adds, a healthy competition between the two women. "Which, I suppose, creates a bit of tension," she says. "[But] they do form an unlikely friendship. You know how films have that bromance, and it's really at the heart of it? It's kind of like the female version of a bromance, I suppose. They've got a really cool friendship." Robbie's character is not in Barker's book, so instead she made a study of television reporters of all ages and demographics, from the current roster on television, and also from the archives, tapping into some of television's historically prominent female newscasters. "To get the intonation right for reporting, their general point of view, and the way they carry themselves in those countries," she says.

Her interactions on set with Fey were more personal. "That's more something we find on set on the day and it's something that's kind of already present on the page which makes it easy," she says. "You can see and feel the banter when you read the script and then it comes to life because you've got someone like Tina Fey who could probably have banter with a brick wall. My job is really quite easy on this one."

The film, unusually, has two directors Glenn Ficarra and John Requa. The pair have several outstanding credits to their names: 2009's I Love You Phillip Morris, starring Jim Carrey, 2011's Crazy, Stupid, Love, which starred Steve Carell, Ryan Gosling, Emma Stone and Julianne Moore, and 2015's Focus, which starred Will Smith.It was on the last of those three that Robbie caught the eye of Ficarra and Requa.

"When we got to the end of Focus I said to them, if you ever want me back I'll do any script, any film with you," Robbie says. "I enjoyed working with them. They work so well and efficiently on set. [As an actor] it makes my life a lot easier." Unsurprisingly given the presence of Fey and her frequent collaborator screenwriter Robert Carlock on the film, there is also room to move in terms of improvisation. "We get a lot of freedom on set to improvise," she says. "We've [also] got an awesome location, there's nothing that I feel isn't going right. It's all going quite smoothly.

"Working with Fey is a dream come true. And a masterclass in improv. I just want to learn anything I can from her," Robbie says. "Improv is] something I personally find difficult but like doing a lot of the time. I feel like it's a bit of a muscle, the more you exercise it the stronger it gets. I'm learning from the very best. She's so quick."

What struck Robbie the most about the tone of Whiskey Tango Foxtrot was the extent to which journalists in remote battlefields are desensitised to their surroundings. "They refer a couple times in the film to the Kabubble they're in, because they're in this insular environment where these sometimes horrific things become so common place that they become desensitised to it," she says.

"It's something that we explored in The Wolf of Wall Street because people would say, oh they were doing such horrible things, but to our characters it didn't seem horrible anymore because they became so used to it and so accustomed to it," she adds. "It's a really fascinating character journey to see the things you end up doing because you've forgotten where that line of what's right and wrong is anymore."

Outside of this sound stage – back in Hollywood – her own environment is something she's slowly becoming accustomed to. In a short space of time this Gold Coast-born girl next door has become one of Hollywood's most bankable actresses. Robbie – who was raised by her physiotherapist mother and spent a lot of time on her grandparents farm in Dalby – threw herself earnestly into acting when she departed the Gold Coast for Melbourne. She began appearing in independent films in the late 2000s until in 2008 along came the character Donna Freedman in Neighbours which she played for three years, winning two Logie nominations.

In 2012, having spent years in acting classes and working with a dialogue coach to perfect her American accent, she moved to the US. She landed a star turn in the short-lived ABC drama series Pan Am before making her big-screen debut in the rom-com About Time in 2013. Pretty much since then her life has been a whirlwind of travel. But she's trying to stay grounded. And she's focusing on little things: an indy film she's developing, and trying to make the right career choices. No doubt that's why the same year she did The Wolf of Wall Street and Focus, she also did the indy film, Suite Française, filmed in France and Belgium. And she threw in a cameo in The Big Short for good measure.

Golden girl Margot Robbie attends the 2016 Academy Awards. Photo: Todd Williamson/Getty Images

"Half the reason you do big films is so that you have the ability to get the small films off the ground," she says. She even harbours an ambition to direct, which is good news when you consider the staggering gender disparity in Hollywood. Women comprise just 13 per cent of the top 700 films, and only seven per cent of the top 250. Female prominence in producing, writing and cinematography is also similarly out of whack. "I would love to direct," Robbie says, firmly. "I want to learn from the best before I set out and do my own things."

In the shorter term she has to contend with getting her comic book groove on for the Warner Bros blockbuster Suicide Squad. The film is an extension of the studio's DC Comics franchise, and will focus on the comic book villains Harley Quinn (Robbie), The Joker (Jared Leto), Enchantress (Cara Delevingne​), Boomerang (Jai Courtney) and Killer Croc (Adewale Akinnuoye-Agbaje).The film is particularly significant because it is the first time Harley Quinn has been played on the big screen, and also – in the wake of a less-than-stellar reception for Batman vs Superman – has the weight of the studio's balance sheet riding on its shoulders.

For a 25-year-old Aussie girl, it's going to be a monumental shift, and will potentially expose her to her largest audience yet. "It's big shoes to fill for sure, it's always intimidating to take on a role that you know could make people so unhappy or on the other hand could make them extremely happy," she says. "It's exciting and intimidating at the same time. Again, like most things in this industry, I'm trying to take it with a grain of salt to some extent otherwise you just get too overwhelmed to do the job at hand."

What matters, she says, is that she's happy. And not that homesick, at least for Erinsborough. "I'm always homesick but the weird thing is now that I've had so many homes I get homesick for all the other places," she says. "At the moment I'm more homesick for London than I am for Australia and when I was away I was homesick for Santa Fe. I've been lucky to have a lot of different homes now and I get homesick for all of them."

Whiskey Tango Foxtrot is released on May 12.