The Canadians dominated the match, establishing a 5-0 lead in the first half.
Andrea Burk's penalty kick added to Canada's lead early in the second half, making it 8-0.
Harvey's conversion made it 15-0 after Canada's forwards pushed the ball over the goal-line with an Australian in the sin bin.
Captain Kelly Russell scored Canada's final try on passes from Julianne Zussman and Emily Belchos.
Howlers Kayla Mack, Maria Samson and Amanda Thornborough were also part of the Canadian squad
Canada's next match will be June 10 against New Zealand's Black Ferns.