Apart from her writing, Bruce seems to have led a life similar to that of many other unmarried middle-class women of her time, devoted to family duties and voluntary work. She looked after her invalid mother and later her ageing father, and helped to bring up her brother's three children after his early death. For more than 30 years, from about 1916 to the late 40s, she was engaged in the Girls' Guildry. This was a uniformed girl's organisation founded in 1900 by Dr William Francis Somerville and originally associated with the Church of Scotland, but later spread over other parts of Britain and the Empire. She was for a period in the 30s President of its West London Centre. She contributed factual articles to the "Lamp of the Girls' Guildry" magazine and Girls' Guildry plays a role in her "Nancy" series and gets a mention in her Dimsie series. In July 1965 The Girls' Guildry merged the Girls' Life Brigade Service of England and the Girls Brigade of Ireland to become the Girls' Brigade.