Coming from a farming family in Témiscouata, Rose-Aimée Gamache is originally a teacher in the Rivière-du-Loup region where she is inspired to create school gardens. Entering the Grey Nuns in 1920 at the late age of forty-two, she obtains the following year a diploma in agriculture from the École Supérieure d’Agriculture in Sainte-Anne-de-la-Pocatière.

Returning to Montréal, she devotes almost her entire religious career to the Saint-Charles Farm in Côte-de-Liesse. Initially, she is assigned to teach at the Notre-Dame-de-la-Paix Agricultural School in a program for orphans interested in agriculture. When the school closes in 1926, she takes on the positions of farmer, accountant, treasurer and local superior, using her scientific knowledge of agriculture, biology, rural economy, chemistry, physiology and botany to organize one of the largest and most prosperous farms in the Province of Québec. In recognition of the excellence of her work, she is named Commander of Agricultural Merit in 1940 and receives the gold medal of the order.