Scarborough was not a researcher, she relied on other people's opinions and some collector told her this- that it was Irish. Very curious! The supposition is that it has to be Irish since Child's ballads were English and Scottish and it wasn't included :) Barmy indeed!
I did find this in Fraser's Magazine, Volume 3, edited by James Anthony Froude, John Tulloch; 1831
"The Drowsy Sleeper, which still exists upon a halfpenny broadside, where it is recommended as "a new song," — the Farmer's Daughter, and the Roving Beggar Man, with many more, may readily be enumerated as specimens of the old English minstrelsy popular in Ireland, and which certainly appear to merit preservation. But it is requisite that we should pass on rapidly to the commencement of the last century, to gain a position more generally interesting than those usually chosen by antiquaries."
They called the broadside a "new ballad" in 1831. Do you suppose this was printed in Ireland? Are there Irish broadsides?