Born in Pittsburgh, Pennsylvania, Johnson is of African American and Puerto Rican descent. Johnson's beginnings in show Business are attributed to her uncle, David W. Duclon, a successful Screenwriter and TV Producer who, early on, was known for his work on Happy Days in the 1970s. Duclon encouraged his niece's Desire to act, and secured her an audition. In 1984, after two seasons as executive Producer of NBC's Silver Spoons, Duclon successfully pitched a new pilot to the network about an orphaned young girl who is taken in by a curmudgeonly older man. The concept won the approval of NBC programming chief Brandon Tartikoff, who named the titular character, and series, Punky Brewster (after a girl he had known in his youth). Johnson was cast by NBC in the role of Punky's (Soleil Moon Frye) best friend, the character of which was modeled and named after herself. Punky Brewster was an immediate success among young audiences, and Johnson continued as the fictional Cherie throughout the series' run (1984–86 on NBC, and 1987–88 in first-run syndication).