Everyone who is puzzled if the girl is involved in something sketchy,read the sentence properly that said she works at a reputable place but some places goes beyond regular.They used- but,indicating that the reputable place itself does not offer those services.So the plot is safe to read
It not about the sentence, but the author intent, and the way it is portray.
So yeah, it is not a prostitute, but still aspired to be one.
Like the trope that give you the ntr feeling without technically being ntr.
It still design to give you that feel you get when reading ntr, so it a deception to yourself that you are not reading it while slowly falling into the abyss.