[6] Armstrong and Robinson co-wrote "Easy on Your Own",[7] a track on Australian Crawl's second album Sirocco and B-side to the single "Errol".
[8] Armstrong moved to the United States in 1981, where she studied under Herbert Berghof and Uta Hagen at the HB Studio[9] in New York City on an acting scholarship.
[4] In the US, she starred as Christine in Tom Stoppard's Dalliance at the Long Wharf Theatre in New Haven, Connecticut,[12] had an ongoing role in daytime serial One Life to Live, and became part of The Actors' Gang along with John Cusack and Tim Robbins.
[4][5] In the early 1990s, she resumed acting in Australian television series, including Police Rescue, Ocean Girl, Come In Spinner, All Together Now and Halfway Across the Galaxy and Turn Left.
[citation needed] When SeaChange ended in 2000, Armstrong continued on with her theatre work and also appeared in Lantana, the award-winning Ray Lawrence film also starring Anthony LaPaglia, Barbara Hershey, Geoffrey Rush, Glenn Robbins and Vince Colosimo.
[citation needed] In 2002, Armstrong joined the cast of medico-legal drama MDA on ABC alongside Jason Donovan and Shane Bourne.
After MDA, Armstrong appeared in films One Perfect Day, Oyster Farmer,[2] Virus, Car Pool and Razzle Dazzle.
[19] Armstrong has worked with several charitable organisations including Childwise,[5] Big hART,[20] and Cure for Life Foundation which sponsors research into brain tumour treatments.
[22] Armstrong has publicly opposed the War in Iraq, and in protest, sat on the steps of the Victorian Parliament in a purple bra to draw attention to her cause.
[5] In October 2008 Armstrong appeared as the face of a "myth-busting" advertising campaign for Coca-Cola Amatil, created by the agency Singleton Ogilvy & Mather.
Claiming her three boys called her "Mum, the myth buster", Armstrong rejected suggestions that Coca-Cola "rots your teeth", "makes you fat" and is "packed with caffeine".
The ACCC's chairman, Graeme Samuel, said, "Coke's messages were totally unacceptable, creating an impression which is likely to mislead that Coca-Cola cannot contribute to weight gain, obesity and tooth decay".