The Merry Old Woman is taken from Irish Folk Music by Francis O’Neill (Chicago, Regan, 1910) p. 341. The version there is given in D; I’ve transposed it here to C and added some simple suggested ornamentation. O’Neill’s score includes the note, “From The Complete Petrie Collection (Compiled early in the 19th Century.)” Research finds several books with a title similar to Complete Collection with Petrie as author or co-author, and I’ve been unable to determine exactly which book is being referred to. The note at any rate indicates that the tune is an old one and is presumably authentic. To complicate matters, I’ve found references to a number of other tunes with this or a similar title, none of which is identical to the tune given above, and most of which to my ear bear only a vague resemblance to it, though one or two are close enough that they might be considered variants. The Merry Old Woman is also given as an alternate title to the tune posted on this TheSession.org site under the title Wallop The Potlid (https://thesession.org/tunes/1454), but that also seems to me only vaguely similar to the tune I’m posting here. At any rate, the triplets are such a prominent and characteristic feature of this tune – not just mere ornamentation – that I wouldn’t call any version lacking them a variation of it.
O’Neill gives some further information on the tune on p. 100:
One often wonders why a popular tune passes current for years without a name among non-professional Irish musicians. Nothing is more common than to be told on making inquiry, "I never heard the name of it," and seemingly nothing concerned them less than the name as long as they could play a tune to suit their fancy. Such was the case with the fine old traditional tune, the "Merry Old Woman." None of our best performers had any name for this favorite jig, so it could not be permitted to remain nameless any longer. By dint of persistent investigation we eventually learned that it was known as the "Walls of Enniscorthy." Few double jigs equal it. None excel it and I’m inclined to believe that it is one of "Old Man” Quinn’s tunes preserved to us by Sergeant Early. A variant of this jig I find appears in Dr. Joyce’s late work under the name, "Rakes of Newcastle-West," but in a much simpler setting.
If I understand this (and it seems a little unclear,) O’Neill found that no one could put a name to this tune when he collected it, so he named it The Merry Old Woman himself, later discovering that the tune was sometimes known as Walls of Enniscorthy, and is a variant of the tune called by Joyce Rakes of Newcastle-West, but he kept the name he had given it for his book. The only version of Walls of Enniscorthy I’ve found is the one on this TheSession.org site (https://thesession.org/tunes/11514), and to me it sounds like one of the ones only vaguely similar to the above.
Whatever the complications, it’s a lively and memorable tune. I assume “Merry” here means “tipsy,” and the tune definitely to me at least has a tipsy atmosphere to it. I’ve written several adaptations of it myself, one of which, for piccolo, under the title “Irish Dance,” has been recorded by the flutist René Stauffenegger and can be heard on YouTube: