Having twins is rare enough and two sets are even rarer. But together, these 4 girls are the rarest of siblings in the world. Baby Maya and her sister Leah are literally two in a billion. While identical, the twins have different hair and skin colors. But that’s not all. Believe it or not, their older sisters are also twins who are on opposite ends of the skin color spectrum. Specialists say they are the result of a rare genetic mix. Mom is white, dad is black and the children, well, as they put it, balance equally. Amazing!