In the 1970s she was one of four founding partners of the first all-female law practice in Ontario, with Mary Cornish, Lynn King, and Geraldine Waldman; the firm evolved through several iterations, including Cornish King Sachs and Waldman, where Sachs remained a partner until her judicial appointment (Law Society of Upper Canada announcement; Waldman & Associates – firm background).
She practised criminal defence and civil litigation alongside her husband, Clayton Ruby, of Ruby & Edwardh (and later Ruby & Sachs / Ruby Sachs), regularly appearing as co-counsel with him in constitutional and civil-rights litigation.
She acted as co-counsel with Clayton Ruby in the landmark Michelle Douglas v. Canada Charter challenge to the Canadian Armed Forces' ban on lesbian and gay service members. The action was filed against the Department of National Defence in 1991, and on October 27, 1992 the Federal Court of Canada, Trial Division (MacKay J.) approved a settlement that ended the policy and awarded Ms. Douglas compensation (Douglas v. Canada, (1992) 58 F.T.R. 147 (T.D.); The Lawyer's Daily / Law360 – Ruby tribute).