That bit about the king/ queen is suggestive. Songs didn't arrive from nowhere; they were constructed on a cultural and historical template. Or to put it another way, existing songs were adapted to local current conditions. This is possibly a song originally about a much older event, adapted for the Civil War.

A young lad called Jim O'Sullivan from Rossmore (but which Rossmore?) was killed at Kilmichael. There is a Rossmore in Tipperary; Dinny Lacey was from Tipperary However Sullivan joined the IRA apparently in Kilmeen in Carberry (Cork), so this isn't much of a lead. But the times were so confused that it's possible that there was an action in Tipperary that went unrecorded.

It would have been a bold action to give them houseroom at the time; if it had been found out, the hosts could have been summarily executed.