Patricia Ward Kelly starts her one-woman show, “Gene Kelly: The Legacy,” by addressing a few pertinent questions about her late husband: he was 5′ 8″; he got his distinctive facial scar from a tricycle accident as a kid; and they met while filming a TV documentary series about the Smithsonian. She also candidly addresses the question perhaps most on the mind of curious audience members expecting to see a frail, 90-year-old woman, instead of the vibrant young speaker before them: when they met, she was 26 and Gene was 73.