As in children.
As in "please hand this to the girl at the window" (meaning the highly trained, apparently competent 50-something person entrusted with sensitive papers and distressed people) and "just sit there and one of the girls will call you back. "(Ditto)
At first I tried being confused. "I don't see any girls here." (blank stare...right over there, can't you see?) Then I tried being shocked. "Surely you don't hire children to work here." (puzzled cluelessness. "No, of course not". ) Then I tried the direct approach. "It's so demeaning to call the professionals you work with girls." This approach was to the male techs who were waiting around to put a cast on my son's arm. (Funny, nobody called them "boys". ) However the response was quite revealing. "Well, they act like girls!" one of them guffawed. His partner sensed dangerous territory and hastened to add. "Of course, they think we're nuts too!"At the Mamogram office this morning, when told by the clerk to wait for the "girl" to call me back, I said again, "It's so demeaning to imply that the people who do such important work are children." The clerk was taken aback and finally responded. "I'm sure its a term of endearment." But I saw a shadow cross her face as she heard her own words. No doubt employee relations are just fine in that big office, but it was crystal clear that the person who was going to call me back was not "dear" to the one who had just called her a girl. It's not really a term of endearment, after all. No, actually, it's a term of belittlement. It bespeaks a lack of respect for persons doing important but adjunct work in a medical office because of their sex.
Call her a tech or a receptionist, a nurse or a patient rep. (hey, then I know more about what I can expect from her!) Call her a lady, a person...heck, call her a woman.
If you play bridge with "the boys" or go out with "the girls", that's your affair. But if you refer to the woman in your office who is older than I am as a "girl" you belittle her, and her work, and by extension, you belittle me.