Stein began practising as a lawyer in 1991 at Fisher Jeffries, where she stayed for ten years, eventually becoming an equity partner.[5]
In 2001, Stein was appointed to the Crown Solicitor's Office as an Executive Solicitor. She was promoted to Special counsel in 2017 and Assistant Crown Solicitor in 2018 and headed the Civil Litigation division.[5][7][11] She was appointed Crown Solicitor in 2020, the third woman to hold the role.[4][6][12] She oversaw the government's disputes in the building of the new Royal Adelaide Hospital as well as the development of emergency laws during the Covid 19 pandemic.[13]
Stein is a member of the Legal Practitioners Education and Admission Council and the Audit and Risk Management Committee of the Courts Administration Authority.[3]
In September 2021, Stein was appointed to the Supreme Court of South Australia.[3][4] She chairs the court's special classification trial management committee and the respectful behaviours committee's steering committee, and belongs to the workplace conduct committee.[5]
Stein was sworn is as Chief Justice by Governor Frances Adamson on 19 February 2026,[14] succeeding Chris Kourakis.[15] Stein was sworn in on a Bible that belonged to Australia's first female judge and governor, South Australian Dame Roma Mitchell.[14] Attorney General Kyam Maher said of her appointment, "Justice Stein’s leadership role in building cultural change in the legal profession, following the Equal Opportunity Commissioner’s report on bullying and harassment, makes her uniquely well-placed to lift standards across the profession as Chief Justice."[3]