At age twelve, Dunbar and her family moved to Manchester, Vermont as a result of her father's involvement in a serious patient litigation. Dunbar was strongly influenced by her mother, her grandmother and her aunt. Her mother was the head of household and an ardent feminist. Dunbar's grandmother, Sarah Ide Flanders, was a widow of an Episcopal priest. Her aunt, Ellen Ide Flanders, once expressed interest in becoming a medical missionary. Many of her characteristics; shrewd, manipulative, stubborn, and domineering, were later also used to describe Helen. Dunbar was also influenced by her father. She was very introverted and highly gifted, mirroring her father's shy and semi-reclusive nature. Dunbar was a lifelong Episcopalian with high church inclinations even though she was largely non-practicing in her later years.