Complex sentence: In 1971 she and her teammates were the first group of teenagers to complete the crossing of the Catalina Island Channel in California, and has twice held the record for the fastest crossing (men or women) of the English Channel (1972 and 1973).
Split into simpler sentences: In 1971 she and her teammates were the first group of teenagers to complete the crossing of the Catalina Island Channel in California. She has twice held the record for the fastest crossing (men or women) of the English Channel (1972 and 1973).