I think Audrey became too popular and they hesitated. She's definitely a Mean Girl in the pilot, and I know that they had a plot planned where Audrey was responsible for her brother's condition (she pushed him off the stairs). Audrey ends up being the ONLY person in "Twin Peaks" who has no deep, dark secret because of that, so yeah, definitely set up to be a lot eviler than they ended up going with. Which I don't mind since I love what they ended up doing with her (although, there really needed to be more of it, and less of...being stuck in subplot hell in season two.)