Curtis & Valla unknown

Found in an album, 1920's-1930's era, having other photos of the Gunstine, Gunstunson, and Ness families of Polk Co., MN, and in Washington. Some names are written on the black paper pages, but are very difficult to read. Names I have given to these photos may be based on my best guess of deciphering the writing or research. Mother holding a child.

What are the surnames of this family?