Do you remember Jessica and Elizabeth Wakefield of Sweet Valley High, i.e. the Jekyll & Hyde of the paperback series generation? Jessica was a dazzling and ruthless b*tch who could mesmerize any man with one impeccably-calculated stare. Her twin sister, Elizabeth, was a mind-numbingly boring model citizen who scared off men with her prudishness (all with the exception of one basic vanilla boyfriend named Todd). They looked the same, but they were polar opposites.
I have come to the conclusion that Jessica and Elizabeth Wakefield are the Summer and Winter Me.