Aging gracefully

Not really, no.

From "The Tale of Aragorn and Arwen", Aragorn chose to die at 210 (He's a descendent of Numenor) and, when he did, Arwen is described as "not yet weary of her days and thus tasted the bitterness of the mortality that she had taken upon her". Seems to me like she was youthful at that time, only truly understanding what mortality meant with the passing of Aragorn. It then says that the elf-light in her eyes goes out. She then dies a year later in Lorien, under the dying mallorn trees.

So it seems more like she died of grief, but she is officially described as having died of old age.

She's vegan.