“Our toddler is now at an age where she’s likely to feel a sensitivity to Small Objects,” Kate Zambreno writes in The Light Room, her new memoir about caring for her two small daughters early in the COVID pandemic and amidst the ongoing disaster of climate change. With schools shut down, she develops an obsession with child development and progressive education methods—it is from Maria Montessori that she learns that children go through many “Sensitivity Periods.”