Born in Melbourne to a family of Italian migrants, Benn is best known for her work with the Brotherhood of St Laurence and created a new theory of social work called developmental approach.
She was the first Research Officer for the Leader of the Opposition in the state of Victoria where she helped bring in amendments to the state's Social Welfare Act.
In her retirement she accepted positions for various organisations.
Benn was made a Member of the Order of Australia in 1995, and was added to the Victorian Honour Roll of Women seven years later.