[Amanaduial the archer]

When Elrond said 'her fate is now tied directly to the ring' (sorry if those aren't the exact words), I think he meant it in a more sort of poetical sense. The way he phrased it was quite confusing though, even to people who have read the books; it seemed to actually imply that if the ring was destroyed, Arwen would be as well, which is of course completely wrong.

Arwen's fate was 'tied to the ring' more maybe than the other elves - if the evil continued to affect men, most of the elves would have already departed for the Undying Lands, whereas she would remain and so would be more affected by it's evil.