Canadian women’s contribution overseas was primarily that of nursing the sick and wounded during times of conflict. Thought to be enlisted mostly from religious orders, they were called “nursing sisters”.
“However, the term ‘sister’ was borrowed from British practice and while it probably comes from the medieval and later association of nuns and hospitals, neither the British nor Canadian nursing ‘sisters’ were nuns.” Peter Monahan.
See this source for more information: Nicholson, G.W.L. Canada’s Nursing Sisters (Toronto:Samuel Stevens, Hakkert, 1975).
One of only few statues that Honour women who served their country in WW1
More than 28,000 nursing sisters served with the Canadian Army Medical Corps. during World War One.
They wore blue dresses and white veils and given the nickname “Bluebirds”. Nurses of the Canadian Army Medical Corps. earned the utmost respect amongst troops overseas for valor, bravery and compassion.
Dedication plague to nurses who served. Regina Saskatchewan.
Nurses at a field hospital in France voting in the Canadian Federal Election December 1917. They had only recently earned the right vote. Library and Archives Canada PA 002279. 
ww1monument 
Excellent in photo! In fact, however, the term ‘sister’ was borrowed from British practice and while it probably comes from the medieval and later association of nuns and hospitals, neither the British nor Canadian nursing ‘sisters’ were nuns.
See this source for more information: Nicholson, G.W.L. Canada’s Nursing Sisters (Toronto:
Samuel Stevens, Hakkert, 1975)