Complex sentence: Making her senior international debut, Pierce placed fourth at the 2015 Skate Canada Autumn Classic before winning bronze medals at a pair of ISU Challenger Series (CS) events, the 2015 Ice Challenge and 2015 Tallinn Trophy.
Split into simpler sentences: Making her senior international debut, Pierce placed fourth at the 2015 Skate Canada Autumn Classic. She then won bronze medals at a pair of ISU Challenger Series (CS) events, the 2015 Ice Challenge and 2015 Tallinn Trophy.