Background
Though born to a human couple, Qilué was full-blooded drow, due to the bizarre events surrounding her birth.[4] By the time her mother (the half-elf soreceress Elué Shundar) was bearing the seventh child, the woman—possessed by Mystra—was almost reduced to a husk by the goddess' power that flowed in her body. Believing his wife to be the victim of an evil spirit, Qilué's father (the human Harper Dornal Silverhand) killed her, endangering not only the child's life, but her soul as well, as she would have been completely destroyed by the power of the Lady of Mysteries that was flowing in her. Looking for another pregnant female strong enough to bear the child, Mystra chose a drow follower of Eilistraee, Iliryztara Veladorn, who was leading a group of like-minded drow to found a community on the surface, near the spot where Dornal killed Elué. Iliryztara's unborn daughter had perished during the journey, and that would have eventually led to the mother's death. Since Eilistraee was trying to find a way to save her follower, Mystra offered to replace the dead baby with the soul of the seventh sister, Qilué, to save both. Eilistraee accepted Mystra's offer, and the Dark Sister came to life—and so did the friendship between the Dark Maiden and the Lady of Mysteries.
As a child, Qilué dwelt in Buiyrandyn, a tiny drow settlement in the Underdark beneath the northern Sword Mountains that had spurned Lolth and the other drow gods.
When Qilué was but a child, Eilistraee (in the form of a 9-foot-tall, stunningly beautiful drow maiden) appeared to her, asking her to lead her friends to aid nearby drow in need, and gifting all the drow children holy singing swords (precious blades that sang when unsheathed, capable of protecting the wielder against fear, despair and magicaly induced fascination/domination effects) to assist and protect them in their efforts. Later, a greater mission was awaiting them, as the Dark Maiden manifested again, asking to destroy the Pit of Ghaunadaur, a mile-deep shaft connected to the Sargauth Level of Halaster's Undermountain, from where the god of abominations could have assaulted the surface world. Surrounded by a glowing aura, symbol of Eilistraee's favor, Qilué led her friends from their drow settlement of Buiyrandyn in this quest. With the protection of the Dark Maiden, they fought their way to the Pit, where Qilué faced an avatar of Ghaunadaur. Eilistraee and Mystra used the Chosen's body as a conduit for their power, and silvery fire burned away at the evil god, until it fled for its life, much reduced in strength. The remaining servants of the god fled with their master, and the divine fire melted and sealed the tunnels and entrances used for the escape. Then Qilué collapsed, and her playmates heard the voice of Eilistraee warning that Ghaunadaur had only been driven away, but not permanently defeated, and that he would one day try to return. The voice said:
“You must make a stand here close to the surface world, and you must be ever vigilant against the return of Ghaunadaur. For a mighty city of humans shall rise above this place, and if you are to make peace with humankind and your elven kin of the surface world, this place is best suited for you.”
— Eilistraee, to Qilué Veladorn and her friends
When Qilué regained her consciousness, her experience and the two goddesses' gifts marked her with wisdom and an innate magical talent, which would help the Dark Sister in the role that both goddesses had envisioned for her. In the subsequent years, following the instructions of the Dark Dancer, Qilué and the rest of the Chosen of Eilistraee (the title that the drow gave themselves) started to regularly patrol the region, checking for signs of ghaunadan activity (which often led other inhabitants of the area to mockingly refer those patrols as promenades, even though the Chosen proudly used the term as a name for the temple that they would later build).