In the 1934 British Empire Games in London, she won gold medals in the 100-yard and 440-yard freestyle events and in two relays.

Four years later, at the 1938 Empire Games in Sydney, she won her fifth gold medal in the 4×110-yard freestyle relay.

After ending her swimming career in the late 1930s, Dewar served in the Women's Royal Canadian Naval Service.

[4] In 1934, Dewar was the recipient of both the Bobbie Rosenfeld Award[3] and Velma Springstead Trophy as the best Canadian female athlete of that year.

[2] Dewar was posthumously inducted into the Saskatchewan Sports Hall of Fame in 1967.