In this casual retelling I read it as a neutral noun describing gender.
Substitute the equivalent here with 'guy' and we wouldn't be having this discussion.
Thinking harder, I guess 'gal' would have been more appropriate. But in any case I feel this reveals more about the reader and their proclivity to engage in 'culture-war topics' than anything substantial.
You are, of course, free to assign any motivation to me that you like.
However I am on the older side and the only times I ever heard "girl" used were as a pronoun for a younger person or as a diminutive for a person seen as lesser than the speaker.
For example, my older family members would refer to "the typing pool girls" or "the makeup counter girl" or, by comparison, "the woman at the county clerk's office."
So it is a bit astounding to me, especially now, to hear someone casually refer to someone who is providing a professional service to them as a "girl."
I think the parent was referring to "financial agent" being a professional context, not HN.
Just sounds informal to me, nbd