Aimee Lou Wood wasn’t sure she wanted to be in Uncle Vanya, even as she made her way to the audition. Having trained at Rada, she knew the lineage of actors who had played the prized part of Sonya, and what an honour it would be to star in a West End Chekhov at the age of 25. “But I just thought it was so the opposite of what I would want to do,” she says.

She did have a point. Sonya is a church-going, sexually naive teenager from the backwaters of 19th-century Russia. Wood, at the time, was fresh out of filming the Netflix teen drama Sex Education. Her character opens the first series with a bout of energetic sex that ends in her boyfriend’s faked orgasm. (Connor Swindells, who played the boyfriend, is her real-life partner of two years.)

It’s true that, in this greater context, Sonya might seem a world away. But Wood began to realise Sonya wasn’t such a step, even if the secluded Russian countryside is far removed from the dramas of Moordale, the fictional town in which Sex Education is set. Her character, also called Aimee, goes from being in the “Untouchables” school clique to making discoveries about masturbation. She then becomes the focus of a sexual assault plot line. And Sonya is still dealing with the stuff of teenage upset, from unrequited love to the self-loathing that can accompany those years.

In person, Wood is full of exuberance and speaks with disarming honesty, saying she related to Aimee right away when she read the script. “I started laughing my head off because it was – verbatim – things that I have said.” But she auditioned for Lily, who is played by Tanya Reynolds in the show. Why? “Aimee is one of the popular girls and I just had this complex. I thought they wouldn’t cast someone with goofy teeth as the popular girl in a Netflix show.”

‘Sonya’s basically a peasant’ … Wood with Toby Jones and Rosalind Eleazar in Uncle Vanya. Photograph: Johan Persson

Sex Education is, she says, a show with an amazing “female energy” from its female writers and directors to its messages to young audiences about sex and gender. “The set is so joyful and supportive. And I think it is feminist just because it has female characters that are fully formed, nuanced and multi-faceted. You don’t see that a lot. I knew that when I looked at the script – because there was not one description of how a girl looks. It was always about their soul or personality. Usually, a script will say something ridiculous like, ‘She’s sexy but in a nerdy way’ or ‘She’s pretty but doesn’t realise.’ How do I play that?”

The sexual assault, which takes place on a bus, came from writer Laurie Nunn’s own personal experience and it is the show’s defining #metoo moment. “I felt so honoured because she was trusting me with her story and something that had an effect on her. Like Aimee, she didn’t expect it to have as much an effect as it did.”

The series shows girls coming together for Aimee, becoming each other’s biggest allies. “Yes,” says Wood, “that’s what Sex Education really nails – female solidarity without being too sentimental. They might be doing these micro-aggressions at school because there’s a hierarchy. But, when there’s a real issue, we know that we have to group together.”

Wood’s own school life was the opposite and it has left scars. She grew up in Stockport where her mother works for Childline and her father is a car dealer. They divorced when she was young, and Wood was sent to an independent secondary school. “They were all posher than me. The mum of a friend would take the piss out of my Stockport accent. I was getting so badly bullied, but I pretended none of it was bothering me.”

Aimee Lou Wood with her partner and Sex Education co-star Connor Swindells. Photograph: David M Benett/Getty Images

She speaks about confronting one tormentor a few years ago: “He called me Bugs Bunny all the time. I messaged him and he said he thought about it a lot and felt guilty. It was a catharsis. I would advise people to talk to their school bullies. The chances are they are now adults who feel really bad about it.”

In the end, she made friends by “being the class clown” and it was this that led to acting. She went to the Oxford School of Drama, then to Rada. “I thought everyone was going to take the piss out of my Stockport accent again, but my group couldn’t have been 28 more different people. My best friend had been to prison. I thought it was amazing, and I felt way less alone.”

That diversity, she says, needs to be reflected in the film industry. We meet on the morning after the Baftas and Joaquin Phoenix’s speech about racism. “Part of the reason I didn’t want to go [to the Baftas] was those nominations. When I saw them I thought, ‘You can’t ignore it – and if you ignore it you’re part of the problem.’”

Some period adaptations are leading the way, she says, singling out the new David Copperfield film starring Dev Patel as the lead. “It’s how a period drama should be done, because it’s a novel so you can cast whoever you want.” She is less enthusiastic about Little Women. “I don’t want to see it. Everyone speaks of it as a female-led film. I think that’s great but they’re all pretty white girls. That isn’t radical. Greta Gerwig – come on, hun!”

‘Joyful’ … Aimee Lou Wood with Emma Mackey and Asa Butterfield in Sex Education. Photograph: Sam Taylor/Netflix

The environment at Rada helped her out of an eating disorder she had been grappling with since the age of 16. “They noticed I was tiny and didn’t eat. So they kept a watchful eye on me. I was weighed a few times. I knew deep down in my heart they were completely right, but it made me angry because it meant I had to change.”

Being shown in various stages of nudity in Sex Education has been a source of further liberation. “It’s probably been the biggest shift in mindset for me because I was so afraid of certain parts of myself being seen that I didn’t think were worthy of being seen.”

Her Stockport accent, too, is one of the things that make her so distinctive – and she brings it to Uncle Vanya. The play’s adapter, Conor McPherson, was aware of the difference in tone that Wood’s accent would make: “He said it was going to ping. Where the other accents are soft, melodic or earthy, you’ve got quite a different sounding Stockport ping. Connor thought it was perfect because Sonya’s basically a peasant. She wouldn’t have a posh accent. And she’s got that northern soul that says, ‘Come on, we need to crack on with this.’ So I think the accent suits her.”

Does she want to do more theatre? Yes, she says emphatically. “Theatre is my default but I did notice when I did Sex Education and came back, I got a little bit of stage fright.” So she reread Uncle Vanya and suddenly Sonya didn’t seem so distant. “I thought, ‘Well, she cares about the environment, she’s in love with someone who doesn’t love her back, she’s got all that awkwardness and she thinks she’s ugly. It was the most relatable thing ever.”