She has written the pilot with Guardian journalist Harriet Gibsone.
Walsh plays Ruby, who "never imagined that her life would turn out like this. Single, unemployed, 'the wrong side of 25', suffering from Irritable Bowel Syndrome and still living at home with her parents (Upstart Crow's Dominic Coleman and Green Wing's Pippa Haywood).
"But the time has come for her to truly make her mark on the world, to do something quite significant with her life - make a podcast!"
Joining Ruby on her first ever show are "cool activist" Charlotte and "aloof heartthrob" Barney, played by Sex Education's Patricia Allison and Edward Bluemel, with Omar Malik (Tracey Ullman's Show) also featuring.
Producers tease: "As Ruby desperately tries to impress her guests, will her show Feminism In Your Ears convince them and her family that there's more to the millennial existence than just endlessly scrolling on Instagram?"
Made by Big Talk, the production company behind Friday Night Dinner, Cold Feet and The Goes Wrong Show, the 15-minute pilot was shot in London in February and is directed by Enterprice helmer Ella Jones, with Lara Singer producing.
She worked on last year's Four Weddings And A Funeral television series for Hulu, and she is part of the writing team for forthcoming Apple TV+ sitcom Ted Lasso, in which Jason Sudekis plays a clueless American football coach who moves to England to manage a Premier League football team, despite having no knowledge of soccer.
For updates, click the button below.