It's neat to see one of my ancient questions revived and answered! I wasn't looking for the origins of the "Two Sisters" as a ballad - Child covers its history in great detail in his collection; I was looking for the source of this particular variant.

Becky from Tuscon, I'm the person who posted the Touchstone/Clannad lyrics in the other thread - I don't know if they're the same ones Clannad sings, because I've actually never heard their version. I'm American, and even though I learned this "Two Sisters" version from Irish singers, it has always sounded American to me. Thank you for posting the version from C. Sharp's Appalachian collection and confirming my suspicions.

A few years ago, Nancy-Jean Seigel, who I think visits Mudcat occasionally, was going on a trip to Poland. She was collecting recordings of "Two Sisters" variants to give to a Polish singer who had her own version of the story. I sang this version for Nancy-Jean, prefacing it with a stumbling attempt in Polish to say hello to the recipient (I wrote out what I wanted to say, and a Polish co-worker translated it for me and coached me in how to pronounce it...) So now this American version has travelled to Ireland and back, and from here to Poland!

Now if I could just find where the tune came from...