Her most well-known play is being Prima Facie, which was staged in a West End theatre in London starring Jodie Comer in April 2022, a production which won two Olivier Awards, three years after a highly successful run in Sydney in 2019.

[5] The family moved to Arnhem Land in the Northern Territory for some time when her father worked there,[4] as an engineer in an aluminium mine.

After a gap year in London,[7] which she spent in a large run-down share house with filmmakers and some of Boy George's backing dancers as flatmates,[3] she decided to do a law degree at the University of New South Wales in Sydney,[2] starting in 1987,[5] and did not return to Melbourne after that.

After having to take a long break from both to recover after being struck down by viral encephalitis, she returned to work and completed her master's.

[7] In 2000 she undertook the now-defunct Playwrights Studio program at the National Institute of Dramatic Art (NIDA),[5] working part-time as a lawyer as well as writing plays.

[3][7] After that she worked for the Public Interest Advocacy Centre (and studied for her MA at UNSW), having to take a long break to recover from serious illness in 1995.

[7][5][9] A radio version of the play directed by Chris Mead was broadcast by ABC Radio National on 9 December 2012,[10] An early work, Reasonable Doubt, premiered at the 2008 Edinburgh Festival Fringe at the Assembly Rooms (Edinburgh) directed by Guy Masterson, starring Peter Phelps and Emma Jackson.

[25][26] It is also being adapted as a feature film, with actress Cynthia Erivo set to play the role of Tessa, to be directed by Susanna White.

[29] As of 2023[update] Miller was working on a play commissioned by the National Theatre, in which a judge's son is accused of rape,[34] called Inter Alia.

She has also been working on the film of Prima Facie being shot in London; and two television series,[3] including an adaptation of Heather Rose's novel Bruny.

Other film projects include Dust, like Prima Facie, being produced by Bunya Productions; Life's Too Short (Hoodlum); and Creatures of Mayhem (Matchbox Pictures).

[35] Miller is a member of PEN International, a human rights organisation representing writers in countries where they are punished for speaking out.

[39] As of 2023[update], with her offspring in their early twenties, Miller lives among three cities: Sydney, London, and New York, but likes to get to the family apartment at Burleigh Heads, on the Gold Coast of Queensland, and Brisbane, when possible.

[8] Miller received the 2005 Theatrelab Award,[40] to develop the play SOLD with Cicely Berry of the Royal Shakespeare Company.

[36] In 2018, she was appointed Drama Creative Fellow at the University of Queensland, giving students playwriting masterclasses and a guest lecture.

[20] In 2023, a judge emailed Miller to let her know that they had redrafted their directions to the jury in sexual assault cases, and had included some of the words about witness recollections from Prima Facie.

[49] While working at the Aboriginal Legal Service, Miller met and later married Robert Beech-Jones, with whom she had two children.

She is friends with writer Hilary Bell and Governor General of Australia Sam Mostyn, and godmother to 14 children.