Allurana

Allurana was the wife of Dethorin, whose unfaithfulness to him motivated his lamentations and, consequently, the appearance of the Killmaim axe. With this weapon, Allurana and her lover were slain by Dethorin, who then cast the weapon into the sea.

Speculation
It is presumed, although not certain, that both Allurana and Dethorin were night elves.