Dysfunctional family sitcom Such Brave Girls follows sisters Josie (Kat Sadler) and Billie (played by Kat’s real-life sister, Lizzie Davidson) and their single mother Deb (Louise Brealey) navigating life armed with nothing but poor judgement and self-esteem exclusively tied to people who couldn't care less about them. They're vain, selfish, heavily in debt, pathologically desperate for affection and bursting with misplaced, terrifying love.

Read more about it below and read an interview with Kat Sadler here.

Such Brave Girls is available from Wednesday 22 November at 10pm on BBC Three and BBC iPlayer.

What can you tell us about your character Deb?

She is a nightmare mother from hell but she loves her daughters. Not equally, of course. She much prefers Billie, the little one. But she tries to do her best by Josie, even though she is convinced that she’s from another planet.

Deb is a wily street rat in big earrings. She will do absolutely anything to get the family out of the tens of thousands of pounds of debt they’ve have been left in by her useless husband’s disappearance. That includes lying, cheating, stealing, etc.

What was it like working with the cast?

I love working with them. They are hilarious. Kat and Lizzie are both going to be megastars. It’s a frankly unseemly amount of talent for one family.

How is Deb different to other characters you’ve played in the past?

I’ve played kick-ass cult leaders, no-nonsense Victorian doctors, entitled noblewomen, wild-eyed baddies possessed by evil and David Mitchell’s fantasist motormouthed little sister. But obviously Sherlock was a phenomenon so I still have to contend with people’s memories of sweet kind good lovelorn Molly Hooper. What can I say? Deb is a nightmare and I love her. I really wanted to resist any pressure to make her nicer or more relatable. It just feels so good to be bad. There’s no one like Deb. I love playing her. It’s hands down the best fun I’ve had with a character. I don’t think it gets much better than this.

What did you think when you first read the script?

I laughed. Which I almost never do as although I laugh all the time in real life, on the telly I only laugh at David Earl, Peep Show, Geoff McGivern and Margot in The Good Life.

How would you best describe the family dynamics?

I think it’s fair to say that the Johnson family is a hot mess. Deb is a text-book narcissist, more or less entirely incapable of empathy, and completely convinced that the solution to any mental health problem is marriage. To a man.

Her daughters are basically deranged and quite a lot of the blame for that lies in their dad buggering off and their mum being Deb.

What do you think she sees in Dev?

She sees four bedrooms and an ensuite.

All Deb’s problems will be solved if Dev asks her to move in. He is their “Willy Wonka ticket out of f**king hell”. She doesn’t bridle at his pathological stinginess, addiction to episodes of Grange Hill or deathly dull line in conversation. None of this is a problem. What matters to Deb is a massive house and the end of debt.

Did you have any input into the script?

Kat was really open to us making offers and I made a fair few. But when a script is that good you don’t need to meddle.

Such Brave Girls is Lizzie’s first acting role, did you give her any advice?

She knows everything already and she learns at the speed of light. Lizzie is a force of nature. It is bats that this is her first role. She is going to be Dame Elizabeth in five years’ time.

Any memorable moments from filming?

Most of my most memorable moments involve Paul Bazely and either Vaseline or an unripe banana. Our intimacy coach, the heavenly Elle McAlpine (who just worked on Yorgos Llanthamos’s Poor Things with Emma Stone), made every time we had to do anything in the bedroom (or the kitchen in one case) an absolute laugh. One scene was so funny that Elle had her fist in her mouth to stop from laughing and spoiling the take. That’s a big compliment.

How would you best describe Such Brave Girls?

It’s the story of a 21st century family: two sisters who are “wet for trauma” and utterly unequipped for adulthood, and their glorious, useless mother-from-hell who will happily threaten to slit their throats in their beds if they don’t stop being weird in front of her rich new boyfriend. So, something for everyone.

Lizzie and Kat - and their amazing love interests, played by Sam Buchanan and Freddie Meredith - take care of the Millennials and Gen Z, while me and the divine Paul Bazely are bringing it home for the old gimmers.

Louise Brealey Image: BBC/Various Artists Limited)