She enrolled to do a BA with the intention of going on to study education and become a teacher of French and English.
When the Pram Factory closed its doors a year later, she became a member of the Australian Nouveau Theatre in 1981, and decided not to continue her university studies.
[1] Throughout the 1980s and 1990s, Forsythe worked closely with director Jean Pierre Mignon at the Anthill theatre company in Melbourne.
[2] Her more recent work at Belvoir, Melbourne Theatre Company, Malthouse Theatre and other major Australian theatre companies has included roles in Patrick White’s The Ham Funeral and Night on Bald Mountain, Eugène Ionesco’s Exit the King, the stage adaptation of Tim Winton’s Cloudstreet, and Samuel Beckett’s Happy Days and Endgame.
In 2013 she appeared in an episode of Miss Fisher's Murder Mysteries (S2:E2), "Death Comes Knocking".