Complex sentence: She is ranked 18th in the Biathlon World Cup 2006--07 season, which is her first top-30 rank in the World Cup standings, and her best placing at the World Championships is 34th at the individual event in 2007.
Split into simpler sentences: She is ranked 18th in the Biathlon World Cup 2006--07 season, which is her first top-30 rank in the World Cup standings. Her best placing at the World Championships is 34th at the individual event in 2007.