McNamara was born on 28 September 1853 in Posen,
Prussia (present-day
Poznań,
Poland). Her parents were Paulina Wilhelmina (née Berndt) and Karl Frederick Kalkstein, her father being a civil servant. When she was a teenager, "economic difficulties broke up the Kalkstein home", and she was sent to Australia to live with relatives. She arrived in
Melbourne in 1869 and lived with an uncle for six months, subsequently moving to
Bairnsdale, Victoria, to work as the governess for her aunt Mrs Drevermann. On 26 February 1872, she married Peter Hermann Bredt, a Prussian-born accountant who worked as the secretary for the
Bairnsdale Shire Council. The couple had nine children, three of whom died in infancy; three sons and three daughters survived to adulthood. After being widowed in 1888, McNamara moved to Melbourne and began working as a travelling saleswoman, selling jewellery and sewing machines. She became a political activist and published
Home Talk on Socialism (1891), one of Australia's first pamphlets on socialism. On 9 July 1892 she married William McNamara founding member and secretary of the Australian Socialist League. As a result of his political publications criticizing the banks, William was sent to jail for libel. In Castlereagh St, Sydney, she ran a boarding-house in conjunction with McNamara's Book and News Depot. Bertha McNamara, who has been called 'The Mother of the Labour Movement', carried on agitating for social reform for 25 years after the death of her second husband. In 1896, her daughter, also named Bertha, married
Henry Lawson. Another daughter, Hilda, married prominent
Labor Party politician
Jack Lang. ==Affiliations==