Disclaimer: this may be different from how it actually happened, but this is my version of Celebrian telling Elrond that she's leaving.
May The Winds Guide You To Peace
The halls of Rivendell's palace were quiet. Too quiet. Elrond paced down the long corridor, towards the garden, his Celebrian's favorite place in the whole kingdom. He found her under the willow tree, staring up to the sky. She heard his light footsteps and turned to face him. "Your father shines brightly tonight," she said quietly. He smiled in return, but his grey eyes remained stormy and untouched.
"What ails you, my Lord?" she asked him, standing and wrapping her arms around his shoulders
"'Tis not what ails me, but you," Elrond responded softly, embracing her in return. "Tell me, what is it?" His face fell briefly. "The wound never fully healed, did it, love?"
There was a pause in which she should not meet his eyes. "No," she whispered. "It did not."
"What must I do?" Elrond quickly volunteered, "I will help in whatever way I can."
"It is beyond your power. My heart longs for the Sea, Elrond. Things that this world cannot offer. You know that what I speak is true," she said firmly.
Elrond dropped his arms from around her. He knew it, but he refused to answer her.
"My thoughts have long dwelt on this, and I have chosen. I will answer the gulls, Elrond. I am going to the sea."
"No!" Elrond said suddenly. They had spoken in whispers until then, and the sudden outcry sent a flock of doves out of the nearby bushed and into the sky. He lowered his voice. "My love, you cannot. Arwen, Elladan, Elrohir … they cannot live without you." He swallowed. "I cannot live without you."
"But you will not have to," she assured him. "I will linger here, in essence, and then the day will come when you and the children will follow. And then we will again be whole, in the Undying Lands. Together…"
A sound like a muffled sob echoed through the gardens. But though they both were close to tears, it did not come from Elrond nor Celebrian. Together they whirled to face their three children, standing quietly together in the starlight. Elladan held Elrohir, who was weeping.
"It is true, then, what I have feared," Elladan said quietly, his other hand on his sister's arm. "You are leaving."
"Hini…" Elrond began, but Celebrian silenced him.
"It is true, yes, ion amin. But do not weep, Elrohir, I will never truly be gone." There was silence, then:
"I have seen you," Arwen spoke suddenly. "I have seen the way you stare at the sky, never happy if your feet stand on the ground. You have heard the gulls." She turned to Elrohir. "It will be so, adtarion amin. Ammë will find peace there, won't you, Ammë?"
Elrond smiled. She was so wise for her young age. Celebrian smiled too, ruffling Arwen's hair. "I hope to, iel amin. I hope to."
"But you can't go!" Elrohir broke in. "We need you!"
Celebrian did not answer. As she turned her eyes to the sky, her only words were, "Your father shines brightly tonight, my Lord."
~~~~~~~~~~~~~Translation~~~~~~~~~~~ (feel free to tell me if I made any mistakes!)
Hini- children
Ion amin- my son (literally son of mine)
Atarion amin- my brother (literally son of my father)
Ammë- Mommy
Iel amin- my daughter
