Which original human character is Gordon's wife?

Gordon's wife is Susan Robinson.

Susan was one of the original human characters on Sesame Street and appeared in the show's premiere in 1969. She was played by Loretta Long, while Gordon was initially played by Matt Robinson. The characters became one of the program's central adult couples and later took the surname Robinson.

Susan's role changed as the series developed. At first, she was portrayed largely as a homemaker, but producers responded to concerns about limiting female characters and made her a public-health nurse. She subsequently appeared as a working mother and as an important source of care and guidance for the children and Muppets on the Street.

Susan and Gordon later adopted a son, Miles, expanding the Robinson family. Gordon's sister Olivia and other relatives were also introduced over time. Viewers sometimes confuse Susan with Maria, Gina, or Linda because all were prominent human women on Sesame Street, but Susan is specifically Gordon's wife. Loretta Long continued playing the character until Susan was phased out in 2016.