Though she entered professional acting at just four years old, Allison Mack had to wait until her late teens for her defining role, playing misfit Chloe Sullivan on the hit series, “Smallville” (The WB/CW, 2001- ). Prior to her nine-season stint on the show, Mack amassed a long resume of appearances on television series and in movies-of-the-week and even feature films. Though she had a not-so-auspicious start with “Police Academy 6: City Under Siege” (1989), she found her stride with multi-episode arcs on “Evening Shade” (CBS, 1990-94) and “7th Heaven” (The WB/CW, 1996-2007), while landing