[3] Harcourt was part of a PEP scheme under Darcy Nicholas at the Willis Street Wellington Arts Centre directed by Colin McColl in a play.

[4] In 1990, a sponsored year at London's Central School of Speech and Drama led to an exploration of drama therapy in psychiatric institutions, with the deaf, and in prisons – the latter inspiring her collaboration with writer William Brandt for the solo play Verbatim, where Harcourt acted, solo, portraying nine characters, inmates' relatives, and victims' families.

In The Guardian, reviewer Michael Billington praised Verbatim as "a remarkable solo show about violence.”[citation needed] Harcourt and her mother, Kate, appeared together in Flowers From My Mother's Garden, a collection of shared anecdotes, reminiscences and stories centered on their relationship and family, and co-written by Harcourt and her husband, Stuart McKenzie.

She has appeared in short films directed by each, including Pardington's The Dig (which was invited to Cannes as part of a special NZ showcase) and McKenzie's darkly comic Ends Meat'.

Harcourt was the acting coach on a number of international and local feature films, including Bridge to Terabithia (Best Actress 2008 Young Artist Awards as well as Best Ensemble Cast) directed by Gabor Csupo, Jane Campion's Bright Star (in competition for the 2009 Palme d'Or), Peter Jackson's The Lovely Bones and Heavenly Creatures, Jonathan King's Under the Mountain (Best Foreign Actress China's Golden Lion), Gaylene Preston's Home By Christmas (London Film Festival 2010), Yvonne MacKay's TV series Kaitangata Twitch (finalist for the 2010 Prix de Jeunesse, platinum winner WorldFest Houston), and Taika Waititi's Boy (Sundance 2010, winner Best Film NZFTV Awards 2010).

[10] Harcourt also teaches Professional Level – Teen Acting for Stage and Screen, as the head tutor at Scots College Creative and Performing Arts School.

In the 2023 New Year Honours, Harcourt was promoted to Dame Companion of the New Zealand Order of Merit, for services to the screen industry and theatre.