The meaning “woman who works” has declined in use because of possible confusion with the other meaning, “prostitute.” And the use of girl to refer to an adult woman is often perceived as insulting and demeaning. See also girl.
British Dictionary definitions for working girl
working girl
noun
1.
a girl or woman who works, esp one who supports herself
2.
(informal) a prostitute
Slang definitions & phrases for working girl
worked up
adjective phrase
Angry; excited; distraught: The whole town was worked up over the shooting incident(1883+)