Edwardh has been involved in numerous high-profile Canadian criminal cases: Some of Edwardh's more recent high-profile cases include representing Mahmoud Jaballah and Mohammad Zeki Mahjoub, detained under highly controversial security certificate legislation, and Ronald Smith, a death penalty case involving complicated administrative and constitutional law.
[5][6] Other clients include the National Post newspaper on a case waiting to be heard by the Supreme Court of Canada regarding freedom of the press and the right to protect confidential sources.
[7] Edwardh rarely holds press conferences and is known to be generally reluctant in granting interviews.
In 2008 she formed her own firm, Marlys Edwardh Barristers, and has since joined the partnership of Sack Goldblatt Mitchell LLP.
In 2005 she was the first recipient of the Canadian Journalists for Free Expression Vox Libera award.