She was born in Kapunda, South Australia. She had one sister called Mary and she attended St Mary's Convent until 1889. In 1901 she started the Girl's Realm Guide in Adelaide. The Girls' Realm Guild published one of Rosman's books, "The Young Queen". Rosman lived in England from when she was a young child.

Early on The Observer and The Chronicle published some of her stories. Rosman began her professional career working for Gadfly. After this she worked for the Daily Herald and for the Bulletin. Her writing style was emotive and eloquent.

Rosman's novels include:

• Miss Bryde of England (1915)
• The Tower Wall (1916)
• The Window (1926)
• The Back Seat Driver (1928)
• The Young and Secret (1930)
• The Sixth Journey (1931)
• Visitors to Hugo (1935)