She began working at the age of fourteen in a stationery factory, then became a dressmaker.
During World War I, she worked in a factory making equipment for the armed forces, and while there she joined the National Federation of Women Workers.
She won a scholarship to Ruskin College, where she obtained a diploma in political science.
In 1926, she found a full-time post as the Lancashire Women's District Officer for the National Union of General and Municipal Workers (NUGMW).
[1] Horan was also active in the Labour Party, serving on its National Executive Committee from 1951 until 1958.