The following year, in 2006, Kirkwood took two productions of her second play, Geronimo to the Edinburgh Fringe, under the title The Umbilical Project. The two productions, Cut and Uncut, were an experiment in cutting the cord between writer and production. Uncut was directed by Kirkwood herself and Cut by a completely separate company under the direction of Matt Addicott. No contact was made between the two companies during the rehearsal period, prompting the tag line "Two casts, two crews, two directors, two venues, one new play... no communication".[2]
Kirkwood's third play, Guns or Butter, about soldiers being overcome by the horror of war, was written for the Terror 2007 Festival at the Union Theatre, London.[3]
Tinderbox, a dark comedy set in a fictional 21st-century England, premiered at the Bush Theatre in 2008. It starred Jamie Foreman and Sheridan Smith.[4] In the same year she also contributed to the Bush's 50 Ways to Leave Your Lover. Her version of Ibsen's Hedda Gabler, titled Hedda, premiered at London's Gate Theatre in 2008 to favourable reviews.[citation needed]
Kirkwood's promenade play about sex trafficking, It Felt Empty When the Heart Went At First but It Is Alright Now,[5] was produced by Clean Break Theatre at the Arcola Theatre. Her short horror piece Psychogeography premiered at the Bush in 2008 and was revived at Southwark Playhouse.[citation needed]
In 2010, a fresh and humorous version of Beauty and the Beast was devised by Kirkwood and director Katie Mitchell and written by Kirkwood. It premiered at the National Theatre. in London as Christmas show in December 2010.[6]
In May 2013, Kirkwood's play Chimerica, which examines the relationship between the US and China since the Tiananmen Square protests through the eyes of a former activist, and features over forty scene changes and British-Chinese actors, opened at the Almeida Theatre. The play transferred to the West End a few months later, in August 2013. The play's title echoes the portmanteau word "Chimerica", invented by economists to define the intertwined economies of the US and China.[7] At the 2014 Olivier Awards, Chimerica won for best new play, best director (Lyndsey Turner), best lighting (Tim Lutkin and Finn Ross), best sound (Carolyn Downing), and best set design (Es Devlin).[8]
Kirkwood's next play was titled The Welkin and concerned the case of a woman convicted of murder who claims to be pregnant, preventing a death sentence from being carried out. The play revolves around a group of 12 matrons assembled to determine the truth of her claim. The Welkin was performed at London's National Theatre in the first half of 2020.[18]
In 2021, Kirkwood wrote the play Maryland, which was staged shortly after at the Royal Court Theatre, and later adapted into a BBC dramatic television film.[19]
In June 2022, Kirkwood's play Rapture, opened at the Royal Court Theatre, credited in the marketing under the pseudonym Dave Davidson, and the false title That Is Not Who I Am. The misleading advertisement ties into the themes and world of the story. The play purports to be a verbatim docudrama concerning paranoia and distrust of the UK Government following the 2020 pandemic and ensuing political scandals. It details the relationship, surveillance, and murder of two climate activist content creators, leaving lingering questions about the State's involvement. In the universe of this play, the UK Government has placed an embargo on the Royal Court (or theatre in question) over the contents presented, and the legality of its production are in question. Thus the opening moments of the play include an explanation that the theatre has decided to stage the play covertly. It features both an actor playing Kirkwood and a supposed cameo from the real Kirkwood herself. Kirkwood portrayed this latter version of herself in the original production at select performances.[20]