The Peredhil and their Immortality

[Haldir]

I seriously thought I'd read somewhere that Elladan and Elrohir chose mortality as well... but it's actually not certain what they chose ... *sigh*

[Erana]

I also believe that they chose mortality and stayed in Rivendell during the Fourth Age until they died... But I'm really not sure, if I read this somewhere or if this is just my fantasy...

[Haldir]

I think so too ... I don't think they would have gone to Valinor...

[Eyalan]

Like their sister, father, and uncle, they could make a choice between mortality and immortality, expressed by whether they would follow their father to Valinor at the time of his own departure at the end of the Third Age. Since they are explicitly described as remaining in Rivendell for a time after their father's departure, some fans speculated that they had also chosen mortality. However, J. R. R. Tolkien himself noted that the twins were allowed to "delay" their choices.

source: wikipedia

I think the professor noted that for a reason. He also wrote that Celeborn stayed with them for a while in Rivendell, to depart to Valinor after that:

Celeborn relocated across the Anduin with many of the elves of Lothlórien at the end of the Third Age to found a new, larger realm, 'East Lórien', but left there for Rivendell to join his grandsons Elladan and Elrohir when Galadriel left Middle-earth shortly after this.

Finally, some time during the early Fourth Age, Celeborn left for Valinor himself, and it is said with Celeborn passed the last memory of the Elder Days from Middle-earth.

source: wikipedia

So it could be that Elladan and Elrohir left with him, right?

[Haldir]

Or maybe they stayed for Arwen?

[Anwyn]

I had also read somewhere that they stayed for Arwens sake, or actually it may have been closer to one of them stayed to watch out for there sister while the other choose to sail to Valinor, but I don't recall it being from an offical source so I do think it was more the wishful sentiments of some fan.