Marta was originally meant to be an environmentalist and fill the role of opposition to the Ewing's plans to drill for oil on the Southfork Ranch. Varela told a writer from El Mercurio that "Marta is a sophisticated woman, educated, smart and professional. Immediately I identified with her." She added that she would find her own life experiences useful while playing Marta. When Varela auditioned for the role she was unaware that the writers had planned for Marta to be manipulative. She told Gabrielle Chung of Celebuzz that the writers had been "sneaky bastards" and not told her how the storyline would develop.
