Esther was the daughter of Philip Samuel and A. Elizabeth Messent of Hyde Park. She graduated from the University of Adelaide with a BA in 1928, and was the first woman to be awarded a diploma in Public Administration (1936) from that university. During World War II she was a YWCA welfare officer with the women's services in the Northern Territory, working particularly in Darwin and Alice Springs.
After the war she was asked to set up Saltash College to help meet the returning soldiers' need to be retrained, and she was Principal of that College for 21 years. She named the college Saltash after the town in the south of England which was the birthplace of her great-grandfather, Philip Santo, one of the founders of the Church of Christ in Adelaide. She was treasurer of the Adelaide University Women Graduates' Association 1936-1939, President of the League of Women Voters 1951-1953, a charter member of the Soroptomist Club of Adelaide, member of the Lyceum Club and the National Council of Women, and for some years chairman of the NCW education committee. She was made a Member of the Australian College of Education. She was also involved in the Colombo Plan.
Her family remember her as an unorthodox, autocratic woman, almost Indian in looks - a throwback to her Spanish ancestors. Her sister Ruth was a painter, and her brother, Sir Philip Santo Messent, a prominent Adelaide surgeon.
Her health deteriorated in the 1960s, and she died of cancer at the age of 69 .