Errath skated for the club SC Dynamo Berlin where she was coached by Inge Wischnewski. She was especially strong in free skating. In 1972 the changes in judging rules led to a reduction of the importance of compulsory figures, and this worked to her advantage in winning competitions. Representing East Germany, she was World Champion in 1974, three-time European Champion between 1973 and 1975, and winner of the bronze medal at the 1976 Winter Olympics. Errath was married to Ulrich Trettin, a former East German tennis champion. The marriage ended in divorce. She is the mother of two children.