Why sisters? -- The power of complicated feelings -- Younger sisters and other variations: why sibling trauma is universal -- The sister knot -- Shared minds: empathy and identity between sisters -- "Just like" and "completely different": how sisters find and resist family roles -- Protection and resentment -- Sisters and friends: the interweaving of female bonds -- Group dynamics among sisters -- The power of sister stories -- Success and insecurity: when one sister outshines the other -- Sistering: a lifelong tie.