At the age of 12, when a major forest fire threatened their home in Matsqui (now part of Abbotsford), Sara tapped a message through to New Westminster to call for help.

[4] McLagan worked at the Western Union Telegraph Company in Matsqui and in Victoria, as an operator, tester, dispatcher, and office manager, until she married in 1884.

After her husband's death in 1901, she continued as president and editor of the paper, the largest Canadian daily published west of Winnipeg, with her brother Frederick S.

[4] McLagan was an early member of the Canadian Women's Press Club,[7] and of the British Columbia Institute of Journalists.

[4] McLagan was a founder of the Local Council of Women of Vancouver, and president of the organization from 1898 to 1900.

She was also involved in the city's YWCA and YMCA, and active in the Georgian Club and the Imperial Order Daughters of the Empire (IODE).