The Tin Horse by Janice Steinberg

Elaine was a pioneering attorney for civil and women's rights.  Now in her eighties, she is getting her papers in order to donate to USC.  In the process she discovers some documents that might lead her to her long lost sister Barbara.  Growing up, Elaine was the smart one but Barbara was the charming beauty.  Both fell in love with the same boy but Elaine was sure her intellect and political passion during WWll won his heart.  When Elaine goes to say goodbye before he marches off to war, she discovers she is wrong.  Elaine goes off to college and Barbara is never seen again.  Her disappearance changes the family dynamics forever.  As the mystery unfolds, we learn much about the adage that siblings all grow up in very different families. It also explores what it takes to become the person we feel we were meant to be.