At the 1931 Wimbledon Championships she reached the quarter final and was rewarded with a spot on the British team for the Wightman Cup, the annual women's team tennis competition between Great Britain and the United States. She lost her singles match in three sets after failing to convert any of her seven match points.
She declined to compete in the French Championships in 1933, as because of her religious convictions, she did not want to play on a Sunday.
In the 1933 Wimbledon Championships, she was seeded no. 2. She lost in the final to Wills Moody, five-time Wimbledon Singles title holder.
In 1934, Round won Wimbledon singles. She also won the mixed doubles competition, partnered with Japanese player, Ryuki Miki.
In 1936, Round partnered with Fred Perry, and they won the mixed doubles.
In 1937, Round won her second Wimbledon singles title.