By TOM DIDATO C-I (Camden, S.C.) sports editor When they last met, It’s Tricky dealt Plum Pretty a defeat in the Coaching Club American Oaks at Saratoga on July 23. Plum Pretty gained a measure of revenge on her rival as the Peachtree Stables 3-year-old filly romped to a 7 ½-length victory in taking Saturday’s $750,000 Cotillion Stakes (Gr. I) at Philadelphia’s Parx Racing.