Thankyou, Sandy!  I've never actually heard any of their records (and wasn't even aware of your involvement), though of course I've noticed that their names turn up a lot in the DT; I should have thought to look for a website.  Anyway, that clears up that question.

Marty; the answer to "what does the title mean" may possibly be dealt with in Professor Child's notes on the ballad, but the nearest copy to me is a couple of miles away in the library.  I can tell you that "Wife" was a term used of older -not necessarily married- women, and I would assume that Usher's Well was just a place-name; others may have more to add.

Malcolm