Manadhlaer was the only child of Calpacaro, a Falmarin shipwright, who gave her the father-name Airesarë ("little sea pebble") and Ñandelë, a Noldorin harpist who played to the sea at the inlet of Alqualondë, and gave her the mother-name Celulinda ("flowing music"). At the Kinslaying, both parents were killed before Celulinda's terrified eyes as she hid in an overturned swan-hull, peering through the cracks -- Calpacaro tried in vain to stop Fëanor's men once they drew swords, and Ñandelë was cut down even as she pleaded for mercy for the gentle inhabitants of the Swan-haven. After Fëanor's men left, stained with the blood of other Quendi, Celulinda was discovered by a kinsman. Her cousin Ayandil patched together a damaged boat, with only a crude tiller to steer by, and sailed across the Belegaer, he knew not where -- but away.

Celulinda was found asleep on a strange shore, by which time her cousin had vanished. She was taught Sindarin; still learning it, she gave herself her current epessë. Her Laiquendi saviours eventually blindfolded her and brought her to Menegroth in the heart of Doriath. 

There she met the youngest child of Finarfin and Ëarwen - an unusual Elf-maid whose mother-name was Nerwen, who seemed to see into the fëa of the young orphan. It was Nerwen who planted the idea in Manadhlaer's heart that the kindreds of the Quendi must one day reunite. With a budding talent for healing, Manadhlaer left Doriath, stealing eastward with the help of the Green-elves in exchange for first aid.

At Belegost and Nogrond, she began her long task of preserving the songs of the other peoples of Arda. Much later, she would notate and preserve ballads that mourned the losses of Beleriand and Númenor.

By the Third Age, many other Eldar with a desire to preserve all types of knowledge found themselves under the roof of Elrond Peredhil in his refuge at Imladris. It was here that Manadhlaer made an unlikely friend and was betrothed.

Tragically, her betrothed was wounded by a goblin-blade poisoned with a substance for which no healer of the Vale had an antidote at the time. He died in her arms, and though a friend of his muttered a few hasty blessings, the necessary act of marriage never occurred. Manadhlaer is often referred to as a widow even though she was not actually married, nevertheless; she still wears her silver betrothal ring, even though it is not at all sure whether her betrothed will ever be released from the halls of Mandos.

Acting in her capacity as Rîn of Lósengriol, she wears a circlet of office. At most times, whether or not she is acting on official business, she wears a pink diamond brooch whose stone was a family heirloom, and often keeps a curious adornment close to her in the shape of a black swan whose form has been marred with several deep scratches that no amount of buffing will ever truly remove.