At the 1982 Commonwealth Games in Brisbane, Australia she represented England in the 100 m and 200 m backstroke where she finished seventh and sixth respectively.
She teamed up with Ann Osgerby, June Croft and Susannah Brownsdon for the women"s 4×100 m medley relay where they finished in silver medal position behind Canada and ahead of Scotland in a time of 4:19.04. At the 1984 Olympic Games in Los Angeles, California, United States of America, she participated in the 100 m and 200 m backstroke, reaching the "B" final in both events. She finished seventh in the 200 m backstroke final, but did not progress beyond the heats in the shorter event.
Catherine sometimes trained in the school"s pool under her father.
Her father, Ralph White an ex Royal Navy Diver, was the swimming coach at Barnard Castle School in County Durham where he was a popular member of staff, affectionately known by pupils as "Pa" White.