Harvard professor and New Yorker staff writer Jill Lepore adds another item to her impressive resume with her groundbreaking portrait of Benjamin Franklin’s youngest sister, a mother of 12 who lived in the shadow of her celebrated brother. Through little-studied letters, documents and portraits, Lepore paints a lively picture of the “other” Franklin, revealing her to be as interesting a subject as her famed sibling—who wrote more letters to her than he did to any other person, but who didn’t mention her once in his memoirs.