Last night, I happened to be at a party hosted by a Mr. Malone. His daughter [after 3 sons] was named Molly.
When I asked him whether his daughter was named after the song, he replied that she was.
He added that he had visited Dublin and when he got into a discussion with another lad in a pub the subject of Molly Malone came up. The other lad had a bit of discomfort at that point and when Mr. Malone asked him why, the discomfort grew. When pressed, the other let Malone know that "Molly Malone" is still used as a euphemism for prostitute.
Interesting convergence, hmmm.....alive, alive oh-o...