As someone elese mentioned, I think she's based on a real person.

Part of the reason I both believe and love her character is because 1) I'd act like her if I were in the same position and 2) she bunks the stereotype.

I think that last part is why so many people are having issues with her character. She's a white female Issac Jaffee (see Sports Night).

Give it time. Let the series roll and let her continue to eat away at our preconcieved notions.