After one role as a young mother in ITV series
Doc Martin, Cooper returned to the West Country, working as a cleaner with her brother Charlie. For a while the siblings lived together, and their experiences would later form part of the writings for
This Country. In 2014, she landed the role of PC Garvey in the TV series
The Wrong Mans. In the same year, a pilot based on the Coopers' initial series pitch had been shot for ITV as the (never released) film
Kerry, setting the basis for
This Country. She wrote and starred with her brother, Charlie, in the
BBC Three comedy series
This Country, for which she won a TV
BAFTA Award for Best Female Comedy Performance in 2018. Due to the success of the first series of
This Country, a second series was commissioned and aired on BBC Three in February 2018. In 2019, she played
Peggotty in
The Personal History of David Copperfield and in 2020, she had a part in
Armando Iannucci's HBO space comedy
Avenue 5. She also appeared with her father, Paul, on
Celebrity Gogglebox. In 2022 she played one of the two lead characters in the television sitcom
The Witchfinder, and co-wrote and starred in
Am I Being Unreasonable? In 2023, she participated as "Otter" on the
fourth series of
The Masked Singer and starred in
Rain Dogs. Also that year, she began voicing Tiny the elephant in an advertising campaign for bank
TSB. In March 2025, she starred in the first series of
LOL: Last One Laughing UK, hosted by
Jimmy Carr and
Roisin Conaty, alongside
Richard Ayoade,
Sara Pascoe,
Lou Sanders,
Rob Beckett,
Judi Love,
Bob Mortimer,
Joe Wilkinson,
Joe Lycett, and
Harriet Kemsley. ==Personal life==