I finally made it back to the UVA library yesterday to see if I could find out any more information about Edith Ballinger Price and her mysterious Massachusetts' source. I looked through the other two volumes in Flanders' collection ANCIENT BALLADS TRADITIONALLY SUNG IN NEW ENGLAND. There were other ballads from Price, collected by M. Olney, with the same kind of cryptic note about "learned in childhood from a friend in Massachusetts" but no new information. One note made reference to 1910 "when she [Flanders] was very young". I also looked at some of Flanders' earlier collections, from Vermont and an earlier collection of New England songs and ballads. There was no additional information in any of these works. In fact, Flanders had incorporated some of the material in these earlier works into ANCIENT BALLADS. So for now, that's all I have been able to find on Edith Price and her source, leaving us no closer to a definitive answer than before.
I would welcome some additional discussion on this subject from New Englanders, and especially from some of the many ballad singers from that region. I think that the questions raised by the study of this one ballad probably apply to the overall status of the old "English & Scottish" ballads in the Northeast.