Actress and novelist known for her role as Nurse Patsy Mount on the show Call the Midwife. She also played Agnes on Chickens and had a role in the 2012 movie adaptation of Anna Karenina.
She started acting in theatre while studying English at Oxford University. She appeared in her first TV show in 2006, but didn't consistently appear onscreen until 2010.
After writing two children's books, Shiverton Hall and The Creeper, her first adult novel, Monsters, came out in 2015.
Her sister is fashion designer Coco Fennell.
She's appeared alongside Helen George on Call the Midwife.