Complex sentence: She captured the New York Filly Triple Crown--the Acorn and Mother Goose Stakes and the Coaching Club American Oaks, all grade I--plus the Alabama (gr. I) and Rare Perfume (gr. II) Stakes.
Split into simpler sentences: She captured the New York distaff secne, and won the former three races that made up the Triple Tiara--the Acorn and Mother Goose Stakes and the Coaching Club American Oaks, all grade I, winning it at the time. As well as the Alabama (gr. I) and Rare Perfume (gr. II) Stakes.