I think the problem was the writers trying to have it both ways, on one side she acts like an antagonist, committing near-evil acts yet on the other side the writers seem to want her to be seen as some kind of adorable, cute and not so bad to test out some romantical chemistry with Dean.

Well, that was doomed to failed. Either she is an antagonist or she is not. The idea of the character was good but so far the execution hasn`t worked. Needs a major overhaul.