Frank,
I hope your friend's memory improves and he/she remembers where it was. The broadside has a tune citation "Lavender Green, &c.". In the 19th century it was often thought that such tune titles were 'internally inspired' from the broadside itself, but we now know better. This is solid evidence that the broadside version is based on a popular song of the time. Such broadsides were usually expanded versions of the song, but a few borrowed the verse form, tune, and initial setting, but then developed quite differently from the original song.