It’s hard to imagine that anything new could be said about the life of Louisa May Alcott, one of America’s most beloved authors. Yet as a great-niece of Abigail May Alcott, Louisa’s mother, Eve LaPlante isn’t just any biographer.

Her new book, “Marmee & Louisa,” is a dual biography — an intimate portrait of mother and daughter, showing how their lives were profoundly intertwined in ways that some biographies have underplayed or ignored altogether. The inspiration for this book — which spans the 19th century from Abigail’s birth through the deaths of Louisa and Anna, the last of her children — came when LaPlante rummaged through her mother’s attic one day and found an old trunk of ancestral belongings. “Who is Louie?” her daughter asked.