In January 1932, Dennis broke the 110-yard Australian record and then the 200-metre world record, gaining automatic selection for the Olympic team at the age of 15. Due to financial difficulties caused by the Great Depression, Dennis managed to attend the Olympics only after assistance was rendered by the Police Department for travel and uniform costs. On arrival, Dennis was hit by illness and then contracted a toe infection after gashing it on the starting platform. Her chances took a boost when Lisa Rocke, who had claimed her 200 m breaststroke world record, was not sent to represent Germany.
