Morgan began serious training in early 1956 and won Olympic selection for the relay team as well as the 400-metre freestyle. Morgan's selection in the final quartet raised controversy because of her inexperience in top-level racing and her history of false starts. During the final, she lifted her head out of the water and saw her American opponent ahead of her, prompting her to regain the lead with a late burst in the third leg. Australia went on to win the relay in world record time. In her only individual event, Morgan came sixth in the 400-metre freestyle.