Armstrong's law degree was a Bachelor of Laws from Monash University. The Monash Faculty of Law was established in 1964 and is based in Melbourne, Victoria, with its main campus in Clayton. The Bachelor of Laws is the traditional undergraduate path to a career in law, and the faculty has long emphasized clinical legal education, which gives students practical experience with real clients.
Armstrong worked as a partner of Phillips Fox, a law firm based in Melbourne. The firm traced its origins to 1864, when it was founded under the name P.D. Phillips, and it later grew into one of the largest law firms in Australasia.
The firm later entered an exclusive alliance with the global firm DLA Piper Rudnick Gray Cary and became known as DLA Phillips Fox. Her time with the firm falls within this period of the firm's development, as an established Australian and New Zealand practice expanded its international reach.
She was admitted to the bar in Victoria in 1985. In Australia, lawyers must first be admitted to practice, and in Victoria that process is conducted by the Victorian Legal Board of Admissions. The Victorian Bar, the bar association of the state, admits barristers who have been admitted by the Supreme Court of Victoria and completed an entrance examination and a Bar Readers' course.
