Girl Friday noun a young woman who is very useful to have about the place as an assistant US,1940 From Defoe’s tale of Robinson Crusoe and his Man Friday.
— AmericanSpeech, p. 299, December 1955: “’Mimeo Minnie,’ ‘Sadie, the office secretary,’ and other women Office workers in America”
There is a small office-supply company on Market Street. The sales manager needs a Girl Friday. — Armistead Maupin, TalesoftheCity, p. 25, 1978