An actress since early childhood, Nancy McKeon made her show business debut at age five. Primarily known for her work in television, McKeon appeared in countless commercials during the early 1970s, but remained best known for her role as tough-as-nails beauty Joanne “Jo” Polniaczek on the long-running sitcom, “The Facts of Life” (NBC, 1979-1988).A native of Westbury, NY, Nancy Justine McKeon was born on April 4, 1966. The second child of Donald and Barbara McKeon, the future television star appeared in countless commercials during the early 1970s alongside her older brother, Philip. In 1975,