Elven/Mortal marriages...

[The Saucepan Man]

With the generation of Elronds Children the choices came to an end. They had the choice to go with their father into the west or to become mortal.

So, Findegil, are you saying that, if Elrond's sons chose immortality and sailed west, their children would (assuming they married immortals themselves) automatically be immortal?

Arwen on the other hand had made her choice and not delaied it. She couldn't sail west.

Presumably, with the permission of the Valar, she could (as other mortals did) have sailed to the Undying Lands had she chosen to, following Aragorn's death. But she would have remained mortal and died there. Then again, I doubt that saying goodbye to her family a second time held much attraction for her.