Lady Paton was appointed as a judge in January 2000 and as an appeal court judge and privy counsellor in April 2007.

She is a graduate of Glasgow University (MA, LLB) and was admitted to the Faculty of Advocates in 1977. She was appointed Queen's Counsel in 1990.

She was Standing Junior Counsel to the Queen's and Lord Treasurer's Remembrancer from 1979 to 1981, and to the Office of Fair Trading from 1981 until 1985. She served as an advocate depute from 1992 to 1994. Lady Paton was a member of the Criminal Injuries Compensation Board and a director of the Scottish Council of Law Reporting from 1995 until her appointment as a judge. She was a member of the Parole Board for Scotland from 2003 until 2007 and chairs the Personal Injuries User Group in the Court of Session (2003 to date).

Her publications include "Damages for Personal Injuries in Scotland" (2nd Edition, 1989), and she was an assistant editor on the 8th, 9th and 10th editions of Gloag and Henderson, "The Law of Scotland".  She chaired the Judicial Studies Working Party in Scotland, responsible for the Scottish Equal Treatment Benchbook: guidance for the judiciary (1st edition 2002;  2nd edition 2008).

She was appointed chair of the Scottish Law Commission in 2019.