Complex sentence: Enith Sijtje Maria Brigitha (born April 15,1955 in Willemstad, Curaçao) was one the leading swimmers of the 1970s, who represented the Netherlands twice at the Summer Olympics, starting in 1972 (Munich, West Germany).
Split into simpler sentences: Enith Sijtje Maria Brigitha (born April 15,1955 in Willemstad, Curaçao) was a leading competitive swimmer in the 1970s. She twice represented the Netherlands twice at the Summer Olympics, starting in 1972 (Munich, West Germany).