Lowry's father was an army dentist, whose work moved the family all over the United States and to many parts of the world. Lowry and her family moved from Hawaii to Brooklyn, New York, in 1939, when Lowry was two years old. They relocated in 1942 to her mother's hometown, Carlisle, Pennsylvania, when Lowry's father was deployed to the Pacific during World War II. Lowry started school in Carlisle at the Franklin School; she'd already been reading for three years and skipped the first grade.