Half-elven Lifespan

[Telchar]

Arwen chose Aragorn and accepted mortality, when he passed so did she. Rather out of wish than out of grief - or so I interpret.

In HoME X Tolkien gives a commest going along the lines of: Bilbo and Frodo was allowed to be cleansed of the hurts of Arda marred and were healed. At some point they chose to die and leave this world. Aragorn on the other hand achieved this without assistance being the first to do so since early Numenorean kings. I have no problem beliving that Arwen, although grieved as she was also achieved this when she laid herself down on Kerin Amroth.

Cheers