[1] After her studies, Edmundson acted with Red Stockings, a female agit-prop company, for whom she wrote the musical comedy Ladies in the Lift in 1988.
Coram Boy was named by the Evening Standard as one of the fifty best plays of the century,[7][8][9] and became used as a set text in A-Level Drama and Theatre Studies.
In 2008, Edmundson amended her adaptation of War and Peace, turning it into a two-part play; this production was staged by Shared Experience and Nottingham Playhouse before touring.
[13] In 2010, Edmundson's musical adaptation of Swallows and Amazons was first produced at the Bristol Old Vic, directed by Tony Award-winner Tom Morris.
In 2012, her play about Juana Inés de la Cruz, The Heresy of Love, was produced by the Royal Shakespeare Company at the Swan Theatre in Stratford-upon-Avon.
Also in 2012, Edmundson's play Mary Shelley was produced on a nationwide tour, including the Tricycle Theatre and the Liverpool Playhouse, by Shared Experience.
[18] In 2014, Edmundson's adaptation of the novel Thérèse Raquin was produced at the Theatre Royal, Bath, starring Olivier Award-winners Alison Steadman and Desmond Barrit.
[24][25] In 2019, Edmundson's adaptation of Small Island was produced at the National Theatre, directed by its artistic director, Olivier Award-nominee Rufus Norris.
In 2015, she wrote two episodes of ITV drama The Suspicions of Mr Whicher, Beyond the Pale and The Ties that Bind, starring BAFTA Award-winners Paddy Considine and Tim Pigott-Smith.
[37][38] Edmundson has adapted numerous literary classics for BBC Radio 4, including The Voyage Out in 2006,[39] The Mayor of Casterbridge in 2008,[40] Anna of the Five Towns in 2011[41] and Sense and Sensibility in 2013.