The first six nuns to arrive in Broken Hill came from Singleton in the Diocese of Maitland, and founded the St Joseph's Convent in February 1889. They were: Ann Agnes Callen (Sister Mary Josephine), Margaret Hennessy (Sister Mary Clement), Sarah Gallagher (Sister Mary Gertrude), Ellen Dwan (Sister Mary Patrick), Margaret Morris (Sister Mary Ita) and Mary Griffin (Sister Mary Evangelist). Sister Mary Josephine was appointed Reverend Mother of the Sisters of Mercy by Bishop Dunne. Under her leadership, they visited the sick and poor of Broken Hill, provided a home for orphans, and opened five schools in the town by 1896.

Sarah Gallagher was raised in Murrurrundi and educated by the Singleton Sisters of Mercy and the Dominican Sisters at Tamworth. She entered the Singleton Convent in 1885, a year behind her own sister Margaret (Sister Mary Claude). A year after she was professed, Sister Mary Gertrude joined the Sisters of Mercy at Broken Hill. She was 21 years of age and appointed Mistress of Novices. For the next 45 years, Sister Mary Gertrude worked with the Community. She was Superior of the Broken Hill Convent from 1902 to 1907, and returned to Broken Hill from 1911 to 1917 and 1923 to 1928. She spent some years leading the Mt Barker Community in the interim, and sent a group of Sisters to found the Brighton Community in 1925. She was founding Superior of the Condobolin Community in 1929, and was appointed in 1932 as the first Mother General of the Amalgamated Sisters of mercy of Wilcannia-Forbes, which position she held until a few weeks before her death.

Sources used to compile this entry: Camilleri, Jenny, Some Outstanding Women of Broken Hill and District, Jenny Camilleri (Broken Hill Historical Society/Broken Hill Council), Broken Hill, NSW, 2002.