'Age of consent', oft referred to in this thread, is an arbitrary man-made and variable construct anyhow, not a Law of Nature. There was no such in British law till mid-C19. The girl in the song, taking it to date from earlier than that, and the young narrator, would have been breaking no laws except parental prohibitions — which could, tho, be effective: I seem to recall one version where the mother

"seized her by the hair of her head
And out of the room she brought her
And with the butt of a hazel twig
She was the well-paid daughter".

Now whose version is that? Dubliners, perhaps? Anyone remember?