Bousted taught English from 1982 to 1987 at Bentley Wood High School in Harrow. From 1988 to 1991 she was Head of English at Whitmore High School in Harrow.
From 1991 to 1995, she was a lecturer at the University of York, becoming Director of Initial Teacher Training from 1995 to 1997.
From 1997 to 1999, she was Head of Secondary Education at Edge Hill College, (which became Edge Hill University in 2006), then at the School of Education at Kingston University from 1999 to 2003.[4]
She became General Secretary of the ATL in 2003.
In July 2010, Bousted was awarded an honorary doctorate by Edge Hill University.[5]
Bousted also served until August 2023 on the General Council and Executive Committee of the Trades Union Congress, where since 2019 she (jointly alongside Kevin Courtney) was lead member on issues of digital change.
In September 2016, she was elected as President of the Trades Union Congress for 2016/17.[6]