I have been performing this song for almost 40 years, and while I agree that concrete interpretation is risky, I feel this is the ultimate poem, and as such we ought not look for places and persons as such so much as metaphorical archetypes.
Jamie is the spinster devoted to her father for whatever reason we cannot know, but she is alone, locked up within herself held captive by fears as old as mankind or rather as old as the oldest that women face which is namely their traditional dependence on a man, either a father or husband, and to hide it from the world they put on a mask of porcelain smiles and never let you see them cry. Her father has died, leaving her alone in the world in the greatest anguish imaginable because her one link with the world and any meaning it has for her is gone. The "land where her father died" is the grief and horror within herself in which she must now live forever. No tomorrow promised by today is pretty obvious, but there is a missing word "and" in one of the versions that ought to read (if you listen to Yarrow's performance) "She's the child of emptiness AND yesterday" She's the child of yesterday because she cannot move on and live her life without her father. Of course, we can wax grandiose and interpret Jamie as the whole human race that is in grief and torment over the death of God, but in the interest of keeping it local, I have to disagree once again that the lyric is "I'll sing you three of a womb never filled" which goes back to the fact that she is a virgin spinster devoted only to here father (this used to be not so uncommon). I cannot say what the fourth deepest wound is, but in context with "one of a song without an end" which must be the life she must live forever in grief, "two of a tree that cannot bend" is the immutable inflexible nature of her sorrow, now having had no other man in her life, the fourth deepest wound has to be the death of her father itself taking with him all the love she ever had in the world. I think this has to be one of the saddest songs I've ever known, and I've known a lot of them. Anyway, that's how I see it. Thanks!-MWR