[3][4] Before moving into politics, Leadbeater was a lecturer in physical health at Bradford College, and has worked as a personal trainer.

[6][7] She had previously been a member of the Labour Party but let this lapse following the murder of her sister when she helped found the Jo Cox Foundation on a non-party basis.

[9] In her first six months in parliament, her two longest speeches were tributes to her sister and to David Amess, another MP who was murdered in October 2021.

She argued that the safety of MPs was not being taken seriously enough, and she called for anonymity on social media to become an exception to combat a culture of abuse.

[10] In June 2023 she wrote a report, published by the Fabian Society: Healthy Britain: a new approach to health and wellbeing policy.

"[23] In response to MPs putting forward an amendment aimed at preventing the Bill being debated, Leadbeater noted how society's attitudes towards dying changed over the past decade.

"[27] In the 2021 New Year Honours, Leadbeater was appointed Member of the Order of the British Empire (MBE) "[f]or services to Social Cohesion, to the community in Batley, West Yorkshire and to Combatting Loneliness during Covid-19", when she was described in The London Gazette as "Ambassador, Jo Cox Foundation and Chair, More in Common Batley and Spen".