§ Of the Ruin of Doriath The Silmarillion

At that time Beren and Lúthien yet dwelt in Tol Galen, the Green Isle, in the River Adurant, southernmost of the streams that falling from Ered Lindon flowed down to join with Gelion; and their son Dior Eluchíl had to wife Nimloth, kinswoman of Celeborn, prince of Doriath, who was wedded to the Lady Galadriel. The sons of Dior and Nimloth were Eluréd and Elurín; and a daughter also was born to them, and she was named Elwing, which is Star-spray, for she was born on a night of stars, whose light glittered in the spray of the waterfall of Lanthir Lamath beside her father's house.