Born in Melbourne, Armstrong began her studies at Swinburne Technical College where she took part in various aspects of filmmaking, ranging from designing costumes to assisting director Fred Schepisi on his segment of the anthology film "Libido" (1973). She first stepped behind the camera as producer-writer-director on the eight-minute short "Roof Needs Mowing" in 1971. After briefly working as an editor, Armstrong earned a scholarship to the Australian Film and Television School's interim training scheme for directors. Supporting herself as a waitress, the enterprising student managed to complete three short films, including "Gretel" (1973), a 27-minute work adapted from a Hal Porter short story that was tapped as Australia's official entry at the Grenoble International Festival of Short Films.
In 1975, Armstrong made the first of three films, made over a 13-year period, that scrutinized the lives of three working-class Australian girls as they matured from teenagers to young women: "Smoke and Lollies" (1975), "Fourteen's Good, Eighteen's Better" (1980) and "Bingo, Bridesmaids and Braces" (1988). The director was able to document the lives of these women with precision and care, allowing each to emerge as a personality. Armstrong later assembled the footage into the award-winning feature-length documentary "Not Fourteen Again" (1996) and has not discounted revisiting the women for a fourth time.
It is her eye for detail that has enhanced the various fictional films Armstrong has directed. Alternating between period pieces and edgy modern works, she fashions stories built around strong, independent-minded women, beginning with "My Brilliant Career", which earned seven Australian Film Institute Awards including Best Picture and Best Director. "Starstruck" (1982) was a musical that followed a barmaid who dreamed of being a punk singer. Armstrong's first American film, the underrated "Mrs. Soffel" (1984), told the based-on-fact tale of a warden's wife who leaves her family to run off with an escaped prisoner at the turn-of-the-century. Returning to Australia, she reunited with her "Brilliant Career" star Judy Davis on "High Tide" (1987), a character study of a chance encounter between a rootless singer and the daughter she gave up for adoption. "The Last Days of Chez Nous" (1992) examined the relationship between sisters and the effect one has on the other's family.
The remake of the classic "Little Women" (1994) proved a natural for the director. Armstrong's version of the Louisa May Alcott novel presented a wider social and cultural context than earlier versions, borrowing details from the Alcott's personal life to flesh out the subtexts of class and gender in 19th Century New England that were only alluded to in the book. "Oscar and Lucinda" (1997) examined similar issues with the timeframe moved forward a few decades and the location shifted to England and Australia. A brilliantly realized adaptation of Peter Carey's award-winning novel, the film focuses on two eccentric dreamers who share a penchant for gambling. Like all of her work, the characterizations of the central figures were sharply drawn but with "Oscar and Lucinda", Armstrong demonstrated her gift for narrative. Told in flashback, it is a love story between an English clergyman (Ralph Fiennes) and a headstrong Australian heiress (Cate Blanchett) and Armstrong guides the audience through their heartbreaking relationship, including a stunning set piece that depicts of the transportation of a glass church to a remote area of Australia.
Maintaining her concern for native issues in her homeland, Armstrong has focused her cinematic attention on local artisans, displaying her wide-ranging interests and abilities in several documentaries made for the Craft Council of Australia.