In 1991, when Anna Chlumsky was 11, she was cast in My Girl opposite the boy wonder Macaulay Culkin. Culkin had broken out defending a break-in in Home Alone the year before. In My Girl, they played childhood friends in 1970s Pennsylvania, and Chlumsky more than matched her co-star for glowing charm. Audiences flocked to it. Chlumsky’s world exploded. After a normal childhood in Chicago, she was instantly famous, the centre of her family and the main breadwinner for her mother, whom she employed as her manager.

For all the wealth and opportunity it brought, the experience was traumatic, she says, over Zoom from her home in New York. “I was lucky because I didn’t have any other huge traumas at the time. I’m the baseline of [child stardom] going relatively well. Yet it was only as an adult that I discovered any sense of reliability or security. When I was a child those did not exist, because I was for sale.”

“There’s a huge societal blind spot about young people in the public eye,” she adds. “It’s not just actors and people in the public eye but athletes, musicians, even now these online personalities. Children don’t have agency. That’s one of the things they’re meant to be learning. So when you suddenly put professional, financial, adult and public – often sexualised – pressures on them, you not only open them up to a world that is commoditising and objectifying them. You’re also setting them back from their ability to develop. So when they are faced with [adult life], the tools aren’t there.”

Her sudden fame warped her adolescence, adding Hollywood pressure to the usual teenage social and bodily insecurities. By her late teens, Chlumsky – pronounced Klumsky – had had enough of showbiz. Rejecting Hollywood, she ran away from the circus to go to college. In 2002, she graduated from the University of Chicago in International Studies with a non-showbiz boyfriend, Shaun So, now her husband, and a vague plan to go into publishing. She worked as a fact-checker for Zagat, the restaurant guide, before a stint at the sci-fi imprint of HarperCollins. It was only four years later, after a fortuitous meeting with Roberta Flack, the singer, that Chlumsky felt the lure of acting calling once again. She went to drama school in New York before easing her way back into the industry.

“The years away definitely gave me perspective. Going to college was my first act of standing up for myself and asking myself what I wanted, making my own decisions. You’ve got to start somewhere, if you didn’t get to start at the optimal age.”

Now 41, Chlumsky has come almost full circle. Thanks to her starring role as the long-suffering political staffer Amy Brookheimer in Veep, as well as parts in In the Loop, Hannibal and countless Broadway plays, she is one of America’s most reliable comic actors, a warm presence capable of surprising sharpness. The woman on the other end of the line seems decidedly untraumatised, open and chatty and circumspect about her extraordinary childhood. On a chair behind her, a dog gazes out of the window. “That’s Zaza,” she explains. “She’s 11. Well into her dowager phase.”

Her latest role is in Inventing Anna, Netflix’s new nine-part drama about the “fake heiress” Anna Sorokin, who, as “Anna Delvey”, posed as the daughter of a German tycoon to con the New York glamourati out of hundreds of thousands of dollars before being arrested, convicted and jailed. Ozark’s Julia Garner plays Delvey; Chlumsky plays Vivian, a fictionalised version of a real-life journalist, Jessica Pressler, on whose article the series is based.

“I was in the mood to play a journalist, and discover all these qualities I believe journalists to have,” Chlumsky says. While I wonder whether she means bitterness, poverty or alcoholism, she fills in the gap. “Like, insatiable curiosity.”

I’ve always found a great deal of safety in protecting my privacy

Vivian is our route into this strange story, a kind of fable for the Instagram age. Delvey appeared in 2013, seemingly out of nowhere, talking about plans to start a members’ club. By acting the part and surrounding herself with the rich, powerful and famous, she managed to maintain the illusion of wealth for years before reality caught up. In the series, Sorokin repeatedly insists she is “building something”, despite mounting evidence to the contrary. In a world of people faking it until they make it, she doesn’t quite make it.

“I don’t want to condone Anna’s actions, but I think if she had been an older man, people wouldn’t have been so ready to make an example of her,” Chlumsky says. “There is a patriarchal fear of women who can think for themselves and make their own decisions.” Is Delvey, who played such a beguiling role in real life, an especially compelling figure for actors?

“There is probably a sense of understanding how ephemeral a persona can be, which doesn’t surprise an actor,” Chlumsky says. “We know what it’s like to have to dive into a different way of thinking. Perhaps the skillset isn’t wildly different. Although the legal choices are better.”

Netflix reportedly paid Sorokin more than $300,000 (£221,000) for the rights, which she has used to help repay her victims. Chlumsky didn’t meet her, although Garner did, but being in fancy New York circles, she was only one degree of separation away. “The whole experience of doing this story has been like a snake eating itself,” Chlumsky says. As a case in point, Macaulay Culkin is mentioned in the original article as having been at one of Sorokin’s parties. Did Chlumsky call him to swap notes? “No, I don’t have his number,’ she says, turning slightly more serious, shaking her head, and probably breaking the hearts of a number of cinemagoers who were 11 in 1991.

Having been to stardom and back again, Chlumsky can take the vicissitudes of the career with a pinch of salt. “Anna’s very grounded,” says Iannucci. “I’m sure she learnt a lot very quickly from being a child actress. At auditions I always ask people to improvise and she was delighted to get stuck in.” A sense of humour came in handy on Veep; as Brookheimer she was nominated for six individual Best Supporting Actress Emmys, without winning.

“By number six everybody was bummed, but I told them not to worry,” she laughs. “I was familiar with being nominated. Winning would have been a huge paradigm shift.”

The only time she appears slightly discomfited is when I notice that it’s her married name, Anna So, which appears on her Zoom. She’s protective of her home life. Partly that’s a legacy of her childhood, and partly because the occasional odd thing still happens to her. If you search her name, one of the top results is a story about Marilyn Manson, who bought her character’s severed arm prop after she appeared in an episode of Hannibal. In 2017 the singer told an interviewer: “I ran into Bryan Fuller, the creator of the show, and he said, ‘Oh, I heard you bought all the stuff – I’m the one who created Hannibal.’ I said to him, ‘Tell Anna that I was rich enough to buy her arm and jack myself off with it.’” A weird story, even before the recent 9,500-word piece in Rolling Stone about Manson’s abusive treatment of women.

“The fact my arm was auctioned off is creepy in itself,” she says. “I was a grown-up, not a child, but I still didn’t get any say. And then, with the lewd remark about what he could use it for… if it walks like a duck, you know?”

“I’ve always found a great deal of safety in protecting my privacy,” she says. One legacy of child stardom is a deep and early mistrust of the internet, which has stood her in good stead over the subsequent decades. “I’m feeling validated these days because everyone knows Facebook sucks. I’ve always had a weird privilege of never thinking the internet was real, and knowing that it’s full of lies.”

Back in the real world, at some point this year she will star in a “queer slasher film” written by the Gladiator and Skyfall writer John Logan. She is in the Rugrats revival, voicing the busy but competent mother Charlotte Pickles. Beyond that, she is trying to be a decent mother to her two daughters. The eldest, Penelope, is nearly the age Chlumsky was when she started working. Would she let them anywhere near acting? “The simplest way of saying that is ‘wait till you’re 18’,” she says. “Enjoy doing school plays and shooting hoops and playing. That’s what that time is for. You want to be grown up when you enter business.”

‘Inventing Anna’ is streaming on Netflix now