Trew was a member of the national council of the CCF for eleven years, and vice-president of the Saskatchewan section of the party for eight years. When the Saskatchewan Farmers Union was organized in 1950, she and her husband joined; she became women's district director in 1953, and was elected women's president of the provincial farm union in 1958, a post she held for five years. She represented farm union women at three meetings of the Associated Country Women.
Trew was a part of the national council of the CCF for eleven years, and vice-president of the Saskatchewan section of the party for eight years. When the Saskatchewan Farmers Union was formed in 1950, she and her husband joined; she became women's district director in 1953, and was elected women's president of the provincial farm union in 1958, a position she held for five years. She represented farm union women at three meetings of the Associated Country Women.