Joan Tomlin was a founding member of the Alliance Party and Freeman of the borough of Carrickfergus in Northern Ireland. Born to educated but financially struggling parents, Leonard and Agnes Charlier, she left school at 16 to become a librarian.

She married Denis Tomlin, an electrical engineer in the army, on Boxing Day 1939. When he returned from the war they had seven children, and she worked occasionally as a cleaner or shop assistant to try to make ends meet.

In 1964 the family moved with the four children still at school to Greenisland, a small community eight miles from Belfast. It was a happy time. They enjoyed the Ulster countryside and holidays with Denis in their caravan. In 1969 Denis died and she had to move with her elderly mother and the two children still at school, via temporary housing, to a small house. Joan took a part time job as school secretary at the Catholic primary school.