Yavanna and Nienna are characters (Goddesses) from Chapter 11 of Tolkiens Silmarillion featured in this excerpt:

But Mandos said: 'And yet remain evil. To me shall Feanor come soon.' But when at last the Valar learned that the Noldor had indeed passed out of Aman and were come back into Middle-earth, they arose and began to set forth in deeds those counsels which they had taken in thought for the redress of the evils of Melkor. Then Manwe bade Yavanna and Nienna to put forth all their powers of growth and healing; and they put forth all their powers upon the Trees. But the tears of Nienna availed not to heal their mortal wounds; and for a long while Yavanna sang alone in the shadows. Yet even as hope failed and her song faltered, Telperion bore at last upon a leafless bough one great flower of silver, and Laurelin a single trait of gold.

These Yavanna took; and then the Trees died, and their lifeless stems stand yet in Valinor, a memorial of vanished joy. But the flower and the fruit Yavanna gave to Aule, and Manwe hallowed them, and Aule and his people made vessels to hold them and preserve their radiance: as is said in the Narsilion, the Song of the Sun and Moon. These vessels the Valar gave to Varda, that they might become lamps of heaven, outshining the ancient stars, being nearer to Arda; and she gave them power to traverse the lower regions of Ilmen, and set them to voyage upon appointed courses above the girdle of the Earth from the West unto the East and to return.

These things the Valar did, recalling in their twilight the darkness of the lands of Arda; and they resolved now to illumine Middle-earth and with light to hinder the deeds of Melkor. For they remembered the Avari that remained by the waters of their awakening, and they did not utterly forsake the Noldor in exile; and Manwe knew also that the hour of the coming of Men was drawn nigh.