Áriel was discovered on the border of Lothlorien by a scouting party. She was found conceled behind a bush. No one else was there, but there were signs that orcs had passed through. The elves took her to Celeborn and Galadriel who infered that her family, or whoever she had been with, had been taken by the orcs. They pursued and killed the orcs, but no other bodies were found. Celeborn and Galadriel decided to raise her in Lothlorien.