Thirteen-year-old Mariah Sydnei Gordon, of Evanston, has already compiled an impressive list of acting credentials, including appearing in "A Christmas Carol" at the Goodman Theatre, on "The Chi," Showtime TV series and in numerous commercials. She will next play G in the Gift Theatre's production of "Hang Man" March 2-April 29. Q: How old were you the first time you performed? A: I was around 9 years old. It was a big sporting goods commercial. Q: How did you get that commercial? A: Through my agent.