The eponymous Girls are mum Deb and daughters Josie and Billie, who navigate love, financial struggles and mental health problems the old-fashioned way: scheming. Deb, played by Louise Brealey (Sherlock), is determined to make her family seem normal in front of love interest Dev. Meanwhile, Billie (Lizzie Davidson) is texting her sort-of-but-not-really boyfriend, “if you don’t reply to me right now Nicky i’m gonna kill myself.”

Then there’s Josie, played by the show’s creator and writer, Kat Sadler. Josie isn’t the most optimistic: as she puts it to Billie in the first episode, their joint brand is “death, silence, hate.” Sadler and Davidson are sisters in real life (‘Sadler’ is a stage name). As it turns out, art frequently imitates life.

“Me and my sister are such spin doctors on bad things that happen to us, and being like, ‘Okay, how do we win the PR of this, so we come out on top?’” Sadler says. “’How do we twist this so [it looks like] we benefit?’”

This approach covers everything from Davidson building up £20,000 in debt by spring 2020, to Sadler’s suicide attempts, to being dumped. As Sadler puts it, “all of our bad luck.”

Her approach to writing was equally exhaustive. She conducted interviews with Davidson and their mum to understand how they all see the world. What stood out as particularly funny to Sadler was their shared ability to stay blasé to any situation, no matter how dark.

From there, Sadler underwent a meticulous process of writing and rewriting, which didn’t even stop after cameras were rolling.

“I was writing between takes, I was writing in the make-up chair, I was writing in the car on the way to set. I did not stop.”

In particular, Sadler would work on ‘alts’, or lines that can be substituted in for bits of the script that don’t work during shooting.

“You want to have stuff in the can so if a line doesn’t come out right on the day, you’ve got a back-up. I think it’s a good way of channelling anxiety, because I was very nervous.”

Such Brave Girls subsequently received three nominations at the RTS Programme Awards, including Scripted Comedy. Sadler herself was up for Comedy Performance (Female), while Freddie Meredith, who plays Kat’s beard-cum-boyfriend Seb, was nominated for Comedy Performance (Male).

The show was also up for not one, but two gongs at the Abortion Onscreen Awards, namely Best In-Clinic Abortion Depiction and Best Comedic Abortion. The Awards are presented annually by We Testify and the Abortion Onscreen Project, in partnership with University of California San Francisco research program Advancing New Standards in Reproductive Health. They’re hosted by Mife, an anthropomorphic version of a pill that induces abortion. Just to be nominated is “thrilling,” Sadler tells me.

“I was so determined, regardless of what anyone feels, to put [abortion] into a sitcom, and deal with it in a funny way, and prove it’s not scary.”

When Billie learns she’s having twins, her and Josie retch with disgust. Billie later comes straight to her abortion from work at a kids’ play centre, meaning she sits in the waiting room dressed as the Wicked Witch of the West, beaming. Once she’s called in, she’s told about the importance of wearing nappies during the procedure (‘adult incontinence pants’) in-between sexting.

“It was very important to me to show that there really doesn’t need to be much sentiment involved in that kind of choice,” Sadler says.

It may not make comfortable viewing for everyone, but that was sort of the point.

“You can get lost when you’re writing to please certain people: that’s when your voice becomes diluted. I was trying to be selfish.”

Through it all, Sadler kept coming back to her relationship with her sister.

“We’re the blind leading the blind on so much stuff: I have loved digging into the logic behind why we make those decisions, pushing us to do terrible things,” she continues. “Some people are gonna really resonate with it, and other people are gonna go ‘these women are mad’.”

Therein lies the key to all great sitcoms. Josie, Billie and Deb are erratic, but never irrational. Even the daftest scheme – from revenge plots to reading each other’s diaries to sex contracts – follows a strict, if questionable line of reason.

“It was a mission to myself to prove that you can have your characters in shows do anything, as long as you can understand the logic behind why.”

The method in the madness is arguably what keeps the world of Such Brave Girls so reliably unhinged. It’s easy to keep hatching plots if you think you’re in the right.

“It’s boring having characters be the moral compass for a show,” Sadler tells me, “and that’s not a character that I’m interested in playing, and same for my sister.”

“I wrote down on a piece of paper and had on my wall ‘The more wrong the opinion, the louder it’s said’,” she says.

There are echoes of other amoral sitcoms here. It’s Always Sunny in Philadelphia – which has the vibe of an alcoholics anonymous meeting run by people who are still drinking – was a “huge reference point.” If you’ve not seen it, you could probably string together an episode from the bits that have been turned into memes. 

Cartoons also shaped Sadler’s comic sensibilities. She is full of praise for The Simpsons, in particular its ability to crowbar in jokes and stretch the rules of reality without ever quite breaking them. As you might expect for someone whose writing is so dark, Sadler is also a huge BoJack Horseman fan. Another influence is less obvious.

“I watched a lot of Spongebob Squarepants growing up, and I definitely think that has been responsible for a lot of my sense of humour.”

It’s hard to see how the kids’ show informs a sitcom where a character masturbates over the toilet while apologising to Emmeline Pankhurst. Still, Sadler’s been at it for a while. When it comes to claustrophobically tight-knit family units, Such Brave Girls is not her first rodeo. In 2017, she starred in and co-wrote YouTube comedy short Sadface, which was produced in part by Turtle Canyon Comedy, a hidden gem for Britain’s up-and-coming comedians. Playing herself, Sadler contended with loneliness and an overbearing mother (played this time by Angela Barnes). Sound familiar?

“It’s been on my mind to do a show dealing with a mother-daughter dynamic as I understand it,” she tells me. “I just kept reverting back to it in my head, so I feel like that probably was an early prototype.”

While making Sadface, she was also exploring similar themes in her stand-up. She began performing comedy at Warwick University, quite by accident. 

“I was brave enough to go to one Comedy Society thing, and I thought we were just gonna watch comedy, and then I found myself in a sketch. It all spiralled from there.”

Prior to that, she’d never even considered herself a comedy writer, opting instead to pen short stories and “sad poetry.”

Now, Sadler reads plays to get into the writing headspace, especially to absorb the ebbs and flows of dialogue. Dennis Kelly’s play Love and Money explores how the two are intertwined, which Sadler notes is what “runs through Such Brave Girls, in a way.” The family’s financial problems are no small part of what keeps Deb trying to win over Dev.

At a certain point in their careers, a lot of comedians start to consider if they’re more of a writer or performer. Despite having experience being both, this is a no-brainer for Sadler.

“Writing is the thing that probably keeps me alive. I don’t think I could leave that,” she says. “If they let me keep acting, then that’s great, but writing is where my heart lies.”