:
: It's a possibility, though I doubt if any evidence could be found to point towards a particular character. This is just a personal feeling, but Goldberry never struck me as being "Elvish" in character. Pretty vague, but it's just the impression I get. From the story-line her character seems to hovver on the borders of being that of a simpleton - "Touched by God" as the old phrase describes it.

: Something which has just struck me is that although there are references to Goldberry's connection to water, her name is a woodland name not an aquatic name. "Water-lily" might have been a more apt name ;-)

As for the elvish thing, while I do side with you about her not being elvish, there is the thing about her saying that Frodo is an elf-friend. I guess she could have gotten it from Gildor, but she seemed to be referring to his eyes. I don't know.

I personally believe that Tom is an one of a kind type being. I'm not really sure what he is, and while I do have my theories, I really don't think he falls into the Valar/Maiar class. And I think that if Tom is one of a kind, that Goldberry most likely is too. Though I'm not ruling anything out.