Born in Brownsville, Texas, Cunningham began diving for the Shamrock Hilton under the tutelage of coach Bob Martin in 1948. She dove at the Hilton until 1957, during which time she was the Texas state champion on platform five straight years and missed a berth on the 1952 Olympic team by just three tenths of a point. In 1957, she succeeded Martin as the coach at the Shamrock Hilton - a position she held until 1973, when she became the aquatics director and diving coach at the Jewish Community Center in Houston. She was the first coach of both four-time Olympian Cynthia Potter and 1976 Olympian Melissa Briley Mieras. She coached national champions and all-Americans Scott Pyle, Kelly Jenkins, Tom Neyland, Terri Seipel, Barbara McCarthy, and many others.