Immortality and the sons of Elrond

[Galin]

There's an interesting note from H&S in entry...

'She was not yet weary of her days - In his unpublished letter to Eileen Elgar, begun 22 September 1963, Tolkien suggests that Arwen could have surrendered her life at the same time as Aragorn, but she was not yet prepared to do so. Although she had become mortal, by nature she was still Elvish, with the long view of life held by that immortal race, to whom 'the gift of the One to men ... is bitter to receive.'

Hammond and Scull, The Lord of the Ring's Reader's Companion