Complex sentence: Stefka went to a specialist sports school, but was only introduced to high jump in a Year Six (12-13year olds) athletics meet in Sofia, on a day she is quoted as saying she would never forget (on TransWorldSport interview in 2012).
Split into simpler sentences: Stefka went to a specialist sports school, but only was introduced to high jump in a Year Six (12-13year olds) athletics meet in Sofia. A day she is quoted as saying she would never forget (on TransWorldSport interview in 2012).