
Lords and Ladies of the Silmarillion; Aredhel
t h e w h i t e l a d yAredhel Ar-Feiniel, the White Lady of the Noldor, daughter of Fingolfin, dwelt in Nevrast with Turgon her brother, and she went with him to the Hidden Kingdom. But she wearied of the guarded city of Gondolin, desiring ever the longer the more to ride again in the wide lands and to walk in the forests, as had been her wont in Valinor; and when two hundred years had passed since Gondolin was full-wrought, she spoke to Turgon and asked leave to depart… xxxxxxxx

Lords and Ladies of the Silmarillion; Annatar
l o r d o f g i f t sSeeing the desolation of the world, Sauron said in his heart that the Valar, having overthrown Morgoth, had again forgotten Middle-earth; and his pride grew apace. He looked with hatred on the Eldar, and he feared the Men of Númenor who came back at whiles in their ships to the shores of Middle-earth; but for long he dissembled his mind and concealed the dark designs that he shaped in his heart. Men he found the easiest to sway of all the peoples of the Earth; but long he sought to persuade the Elves to his service, for he knew that the Firstborn had the greater power; and he went far and wide among them, and his hue was still that of one both fair and wise. Only to Lindon he did not come, for Gil-galad and Elrond doubted him and his fair-seeming, and though they knew not who in truth he was they would not admit him to that land. But elsewhere the Elves received him gladly, and few among them hearkened to the messengers from Lindon bidding them beware; for Sauron took to himself the name of Annatar, the Lord of Gifts, and they had at first much profit from his friendship.
It was in Eregion that the counsels of Sauron were most gladly received, for in that land the Noldor desired ever to increase the skill and subtlety of their works. Moreover they were not at peace in their hearts, since they had refused to return into the West, and they desired both to stay in Middle-earth, which indeed they loved, and yet to enjoy the bliss of those that had departed. Therefore they hearkened to Sauron, and they learned of him many things, for his knowledge was great. In those days the smiths of Ost-in-Edhil surpassed all that they had contrived before; and they took thought, and they made Rings of Power. xxxxxxxx
The Silmarillion by Ted Nasmith

Idril was that most fair daughter of the king of Gondolin whom Tuor loved when she was a little maid, and who bare him Eärendel. Her the elves name Irildë; and we speak of as Idril Tal Celeb or Idril of the Silver Feet, but they Irildë Taltelepta.
“The Fall of Gondolin” - The Book of Lost Tales (part. 2) - HoME - J.R.R. Tolkien
tolkien’s own paintings for the silmarillion
a description for the heraldic devices can be found here