Mary Ukaego Nzenwa was born on 12 May 1952 in Amudi Obizi, Ezinihitte Mbaise Local Government Area of Imo State in southeast Nigeria.
The same year, Ukaego gained admission into the University of Nigeria, Enugu campus where she read law.
In her second year at the university, she earned a scholarship for maintaining the second class upper division league with higher scores.
Ukaego and her family moved to Port Harcourt city where her husband founded his medical centre Pamo Clinics.
Between 1980 and 1988, Ukaego served as Chief Magistrate Grade I, Chairman of the Juvenile Court, President, Marine Board of Inquiry into the 1979 Buguma Boat disaster, chairman, Constitution Drafting Committee of the University of Nigeria Alumni Associates, Inaugural Chairperson of the International Federal of Women Lawyers (FIDA) Rivers State and Secretary, Nigerian Horticultural Society.
With her support, Odili entered politics and served as member and leader of Rivers State Delegates to the Constituent Assembly.
[5][6] She was the leader of the Five Person Panel at the Supreme Court that nullified the Gubernatorial Election of David Lyon after his deputy was found wanting for submitting fake certificates during pre-election screening after they were declared winners on 16 November 2019, Bayelsa State gubernatorial elections.