Immortality and the sons of Elrond

[Mithadan]

I do not think that Elros' children had the option of choosing to be numbered among the Elves. Elros chose to be a mortal Man and his wife was mortal as well. The children of Elros were Men and thus could not be denied the Gift of Iluvatar. I do not think that a residual percentage of Elvish blood would change this conclusion.

The Half-Elven created a dilemna for the Valar, which was resolved by a hard and fast rule, at least for those who chose mortality. The applicable quote is

"in this matter the power of doom is given to me. The peril that he ventured for love of the Two Kindreds shall not fall upon Earendil, nor shall it fall upon Elwing his wife who entered into peril for love of him; but they shall not walk again ever among Elves or Men in the Outer Lands. And this is my decree concerning them: to Earendil and to Elwing, and to their sons, shall be given leave each to choose freely to which kindred their fates shall be joined, and under which kindred they shall be judged.

Earendil, Elwing, Elrond and Elros had this choice.

Which circles back to the original question. Did Elladan and Elrohir have this choice as well? Manwe's speech, quoted above suggests the answer here is no. The quotes attributed to Elrond, above, and the excerpts from Letters, suggest the answer may be yes. Arwen's statements are equivocal; she says that she was granted the choice of Luthien, which is a different matter altogether. Yet even Elrond's statement is somewhat equivocal. He says 'That so long as I abide here, she shall live with the youth of the Eldar (...) And when I depart, she shall go with me, if she so chooses.' While this hints at the existence of a choice, it may be that all he means is that she is an Elf and whether or not she departs with him into the West, she remains an Elf.

If we accept Manwe's statement, Elrond's children have no choice. Elrond's decision is binding upon them. If this is the case, maybe only Arwen was granted the choice of Luthien. Given Elrond's grief at their parting "that should endure beyond the ends of the world", it seems clear that she is granted leave to live the life of a mortal Man. She did not merely die of grief as an Elf. Perhaps this is the simplest answer; Elladan, Elrohir and Arwen lacked the choice of the Half-Elven and Arwen's was a special case.