Complex sentence: Unknown to her, a friend entered it in the Great American Play Contest at the Actors Theatre of Louisville, and it was named co-winner and performed in February 1979 at the company's annual festival of New American Plays.
Split into simpler sentences: Unknown to her, a friend entered it in the Great American Play Contest at the Actors Theatre of Louisville, and it was named co-winner. The play was produced in February 1979 at the company's annual festival of New American Plays.