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I've seen it suggested that surely Cordelia had a different mother than Regan and Goneril, how else can you explain the drastic differences in their personalities. What I'm curious about is the difference between Regan and Goneril. Do you imagine them as having the same mother, thus making them real sisters having a stronger bond than they do with their younger sister? Or do you prefer to imagine each from a different mother thus fostering more of the "every sister for herself" mentality that we ultimately see?