There are references in the stories to original samples of Trelle's hair in one of the temples but part of the origin story was quoted in Unification chapter 8.
The first four groupings of First Hymn of Trelle
In Unification chapter 8, Fel wrote:“In the beginning, there was naught but Trelle. Trelle was the totality, the all, the singular being. But Trelle was displeased with the emptiness around her, saying ‘This must not be.’ And so she took her hair and cut it away, and from the strands of her hair the suns and moons and the land was formed. The sight of her creation moved her, and from her eye did a single tear fall, which became the seas abutting the land. She found beauty in her work, but no purpose, so she bent to the task of putting purpose to the land. She pricked her finger, and from the drops of her blood did the creatures who crawl and walk and fly come to be, and she found it good, but not yet as it should be. She touched her finger to her belly and declared ‘from within me shall I bear the Faey, who shall stand in dominion over all.’ And so did she conceive within herself the First Woman, Baala, who was borne from Trelle and then placed on the land which was now hers. “Go forth and rule this land which I have made for you,” Trelle did command unto Baala. And so Baala did as she was commanded, but did so with a heavy heart. ‘Great Trelle, Holy Mother, I am lonely,’ Baala confided. ‘I am always within your eye, but you are not within mine. I am at your touch, but I cannot touch you. Might I have a companion to bring me happiness as I have brought you happiness?’ Trelle responded ‘but I have made you mistress of all, lord over all things. Does this not make you happy that the vulpar and the freba and the greel all give homage to you? Does the vulpar not comfort you when you are sad, or the freba sing to you when you are pensive, or the greel play with you when you are happy?’ And Baala did respond ‘they are but animals, Holy Mother. I cannot speak with them. I would like someone to talk to, Holy Mother, someone like myself.’
“Moved by Baala’s lament, and seeing that the life which she placed upon the world was ephemereal and without the ability to continue itself, Trelle did move to both provide continuance to the life she had made and also provide Baala with her companion. Trelle did touch her belly once again and conceive inside herself another life. She bore forth Demir, the Consort, Swordbearer, and after finding that he was the complement to herself, the manhood to her womanhood, did she install him into her own domain and take him unto herself as her husband. She joined unto Demir as wife to husband, and thus did she conceive once more within herself Aris, the Child Goddess. Pleased with the natural state of things, so did Trelle proclaim ‘so shall it be for all living things, for there to be a mother, and a father, and for them to join together to bring forth children.’ And so did Trelle take a drop of blood from Demir and touch it to Aris upon her belly, and cause her to conceive a mortal son, the First Man, and did Aris make him complement Baala to be her wise and loving companion. This son did Aris name Baaen, and place him with Baala. ‘Thus you are given what you craved, mortal daughter,’ did Trell proclaim. ‘Aris has given unto you her son to be your husband and your companion, the wisdom to complement your strength, which you must treasure and protect as you protect yourself. Go forth and join to him as wife to husband and conceive new life, as I have ordained it to be as nature intended.’ And so did Demir take up his sword and prick his finger, and from his blood did a male come to be to complement every female of every life which crawled or swam or walked or flew, which Trelle did already create, and did the gods thus establish the natural order of things that Trelle designed.”