Born in Gloucester, MA, in 1888, Cunningham graduated from Vassar College in 1910. She then returned to Massachusetts, where she enrolled at the Lowthorpe School of Landscape Architecture (now part of the Rhode Island School of Design), earning a degree in landscape architecture in 1915. A lifelong learner and teacher, she also completed a course at the Cambridge School of Architecture and Landscape Architecture for Women in 1918, and was the only woman to earn a master’s degree in dendrology from Radcliffe College through the Bussey Institution of Harvard University in 1923. A protégée of landscape architect Ellen Shipman, Cunningham taught briefly at Smith College before opening her own firm, first in New Hampshire and then returning to practice in Cambridge and finally Boston, where she lived with her twin sister. Cunningham taught plant design at the Cambridge School beginning in 1919, as well as at Lowthorpe from 1932-33. Along with colleagues Stephen Hamblin and Edith Cochran, Cunningham would lead “rigorous plant hunting hikes over hill and dale, in all kinds of weather,” and she was a sought-after teacher.
Cunningham became a member of the American Society of Landscape Architects (ASLA) in 1924. Her writings on horticulture and landscape architecture were featured in prestigious journals such as Garden Magazine, and she contributed a monthly column to House Beautiful, “Month by Month in the Garden.” She travelled extensively throughout Europe, expanding her knowledge of garden design in Italy, France, and England, and also visited Hawaii, Bermuda, and North Africa. In addition to her prolific writing and teaching career, she designed many formal gardens for private clients, primarily in Massachusetts and Connecticut. The “Hornblower Garden” at Plimoth Patuxet Museums in Plymouth, MA, is a rare extant example of her work and is now open to the public. Cunningham died unexpectedly at the age of 46 when she was hit by a truck in Boston.