Little is known about the life of Nelly Cunow-Detjen (or -Deetjen). She was born in 1893 in Posen, which was then still part of Prussia, but later became Polish. For her art education she went to Berlin, where she stayed for a number of years afterwards. From 1939 to 1982, the painter lived and worked in Eystrup, North Germany, where she probably also died. Nelly Cunow painted and watercoloured in an impressionistic style, mainly summer landscapes and farmyards, but also animal portraits. She bequeathed some of her paintings to the Kreismuseum in Syke, Northern Germany.