A sister is both your mirror - and your opposite. Elizabeth Fishel   Sisters   My sisters and I all look alike. We also sound alike. Strangers or people who don’t know us well are always mixing us up, and when we look at old baby photos, we get mixed up ourselves and have to ask mom, “Which one is it?” Sometimes I suspect that she uses the background, which house we were living in, or which curtains were on the windows, for clues. Or, if she is in the picture, I think she uses her hairstyle as a