Calkins trained with the Calgary Aquabelles. In her first international competition she won a silver medal in the team event at the 1973 World Aquatics Championships in Belgrade, Yugoslavia. She was also a member of the silver medal team at the 1975 Pan American Games. Her most notable successes came with her partner Helen Vanderburg. At the Pan Pacific Championships in Mexico City the pair won Gold for the first time. They won Gold again at the Canadian Aquatic Championships in 1978 in Berlin and were the first Canadian duo to earn gold medals in that event. Calkins retired from competition in 1978.