After re-reading The Atlas of Middle Earth (excellent read recommend it to anyone) I noticed that north of the Pelori in Aman, there was a tower marked as "The Tower of Elwing". I cannot for the life of me remember anything about this tower in the Silmarillion or Unfinished Tales (but its been a while).
Thinking out of the box, I would guess that Elwing retains the ability to transform into the Bird form in which she flew to Vingilot and Earendil after the third Kinslaying, and likes to live by the sea, however this is pure guesswork from me.
Does anyone have any more info on this tower? or at least tell me where I may be able to find more info.