MARY-KATE & ASHLEY OLSEN have turned their design talents to weddings, well, at least one wedding, that of long-time friend and stylist, Molly Fishkin, whose wedding gown The Row designed. Molly married producer/director Asher Levin in the Silver Lake district of Los Angeles, where 130 guests dined alfresco on long wooden tables for a dinner of slow-cooked salmon, flank steak, vegetables, and broccolini with white beans. The dress, of course, was enchanting and romantic, and pure BOHEMIAN perfection . . .