Essi Matilda Forster (née Christian) was born on 12 September 1922 in Sekondi, the Gold Coast, (modern-day Ghana) to George James Christian and Aba Lucy French. Her father who was originally from Dominica in the Eastern Caribbean settled in Sekondi in 1902. He had attended the First Pan-African Congress in London in 1900 and regarded himself as a "returned exile." Her mother was from Shama in the Western Region of the Gold Coast. Essi’s father, George James Christian was a private legal practitioner, a politician, and a businessman. He represented the Western Province of the Gold Coast as an elected member of the Legislative Council for ten years from 1930 to 1940.

At the age of five, Essi was sent to England for her education. Essi made her intentions of pursuing law known to her parents by January 1940. Like her father, she qualified as a Barrister-at-Law and was called to the English Bar at Gray’s Inn, London in November 1945. She was called to the Gold Coast Bar on 15 April 1947 making her the first woman lawyer on the Gold Coast and the third woman lawyer in British West Africa. The first African woman lawyer was Stella Thomas, who was appointed Stipendiary Magistrate in Lagos, Nigeria. Frances Wright from Sierra Leone who also attended Gray’s Inn was the second. In that same year, Essi was also called to the Gambia bar where she practiced law from 1947 to 1951.

Essi was also a wife and a mother. On 17 December 1944, she married Prof. Edward Francis Bani Forster, a psychiatrist from the Gambia. They had three children, Bankie Forster, Ekow Forster, and Estelle Matilda Appiah (neé Forster). Essi moved to the Gold Coast from the Gambia in July 1951 when her husband took up service in the colonial administration as the first African psychiatrist at the Mental Hospital in Accra. She was the Acting Registrar of Companies, Births, and Deaths in Accra for six months. She also worked as the legal advisor to Mobil Oil Ghana Ltd from 1957 to 1982. At Mobil Oil, Essi’s services were so valued by the Company that she was asked to determine her salary when she was engaged. Her appointment as a corporate legal adviser set a precedent in Ghana, allowing all large Corporations in the country to retain lawyers on their staff. She served in that capacity for over twenty-five years.

Essi followed in her father’s footsteps by engaging in many professional and public service activities. She was a founding member of the Ghana International School Committee from 1954 to 1959. Within that same period, she was also a member of the Accra Magisterial District Prohibition Committee. She was a founding member and President of the Ghana branch of the International Federation of Women Lawyers (FIDA) and the Inner Wheel Club of Accra. As a member of FIDA Ghana, she made recommendations to the Ghana Law Reform Commission on intestate succession, widowhood rites, maintenance of children, and abortion.

These were novel areas of law in the best interests of women and children. She also served in the following organizations in various roles: Young Women’s Christian Association (Y.W.C.A.) where she served as the Vice President and Secretary of the Y.W.C.A. Hostel Committee; Ridge Church Sunday School as secretary from 1963 to 1980; chairperson of the Nurses and Midwives (Accra) Schools Board of Governors from 1969 to 1972; President of the Ghana Girl Guides and substitute member of the Constitution Committee of the World Association of Girl Guides and Girl Scouts from 1972 to 1975. Essi considered these professional and voluntary public service activities as essential to a full and interesting life.

After her retirement, she led a quiet life and was known to be one who loved to walk. All who knew Essi, knew her to be a wise woman with a memorable laugh. Essi was described as "fiercely independent” even in her old age and this independence may have contributed to her untimely death in August 1998 when she was fatally knocked down by a motorcyclist in Accra. She died at the age of seventy-five. Essi was the most senior lawyer of the Ghana Bar at the time of her death. She blazed the trail for women lawyers in Ghana and elsewhere in Africa and mentored many
who aspired to be like her.