Note 1: Egalmoth is commented on in The Book of Lost Tales, Part II as having a bent, or rather, curved sword, and is also remarked upon as being the only Noldo to use a curved sword. While, for the purposes of my head canon, I must deviate from this point, I do wonder where he got it from.
Note 2: Ah. Also, for the purposes of my canon, I treat the name 'Egalmoth' as a Sindarin epithet he received in Beleriand, mainly because I can not for the life of me figure out what the Quenya translation of 'Egalmoth' is supposed to be. The books I have (HoME volumes, mostly) are hazy on what even 'Egalmoth' is supposed to mean. Thus, I have given him the Quenya name of Márilo.
I own nothing.
In Beleriand in the years to come, the Mithrim will give him the name 'Egalmoth', but for now he is Márilo, a son of the House of the Heavenly Arch in Tirion upon Túna.
From his grandmother Calairë, a nís of the Falmari, Márilo learns archery. He and Calairë practice archery on the green lawn outside of their home, bathed in the gold and silver light of Laurelin and Telperion. Nearby, Márilo's father and his older sister practice with swords.
Her name is Ilsasírë. She has a crooked grin and a wide nose, freckles on her face and limbs, and long, loose arms that swing lightly when she walks. Márilo and Ilsasírë don't exactly look very much alike. Where his hair is brown, hers is the same silvery-dark as their grandmother's, and her eyes are blue to his gray. Márilo is much taller than her by the time he is roughly forty, by which time Ilsasírë herself is already grown. When the day first comes that they realize that he's taller than her, she snorts and remarks that she's soon to have a giant for a brother, and at least she'll have someone to reach the top shelf when they have to go digging in the pantry from now on.
Among the Noldor, the swords of neri are long and straight. However, for reasons Márilo, not being a sword-smith nor the one who decides these sorts of things, does not understand, swords made for nissi (and they are relatively few compared to the swords made for neri) tend to be gently curved backswords, with only one bladed edge. If the matter is one of concern for the general lesser strength of nissi, Márilo doesn't understand why the sword-smiths couldn't just have made straight swords with lighter blades. This sword of his sister's is barely any lighter than his own straight-sword.
"Papa says that a single-edged blade isn't good for stabbing, either," Ilsasírë comments when they compare. She grins. "I suppose that if I ever have to stab any orcs, I'll keep a knife handy to that effect."
It's supposed to be a time of great unrest, but Márilo barely feels it. He sees it, yes, but no unrest takes root in his heart. At least, not at first.
Ilsasírë, on the other hand, she's different. She talks about seeing Endóre, about crossing the wide waters and seeing the lands where their forebears originated. The starlit lands are to her a place of escape, though what she could possibly need to escape, Márilo can't begin to guess. She sees a place where they can be free, and Márilo does not at first, but as she talks, on and on, he starts to.
When the tumult and terror of the Darkening comes, and the Princes of the Noldor announce their intention to leave Aman behind forever, Márilo's parents and grandparents say that they are staying here: the House of the Heavenly Arch will not be joining the rebels. However, Márilo and Ilsasírë's parents and grandparents speak for neither of them.
It is Ilsasírë who first resolves to leave with their rulers, she who leads the way. Márilo follows after as he has done since they were children (Not so long ago, really). They offer their swords in service to Turukáno, second son of Nolofinwë; many of the sons and daughters of noble houses whose masters are not leaving Tirion have come to him. And after their oaths of loyalty are said, they leave.
They labor through the dark together. They wade through the blood and the horror of the First Kinslaying together, wondering if they will ever be forgiven, if their grandmother will forgive them, if the dead will forgive them, and suspecting that none of them ever will. When Rána first appears in the sky, Ilsasírë makes the connection to Telperion long before Márilo does. They shiver and struggle and starve on the Helcaraxë together, eating their meager rations, going on the hunts—though this time it is mostly Márilo, the better archer of the two, who hunts. "I couldn't hit a deer if it was standing within arm's length of me," Ilsasírë admits ruefully, "so yes, it had best be you."
Then, Vása appears over the eastern horizon for the first time. This time, it is Márilo who first makes a connection between this orb and one of the Two Trees that were lost, golden Laurelin. Darkness vanishes from the land, and the voices of the Noldor rise up in joy and relief that the world around them is lit at last. No longer must they labor through this unnatural, blighted darkness. The world is good and green again.
The battle of the Lammoth descends upon them what seems only a split-second afterwards.
What most remember of the battle of the Lammoth, and indeed, what most chroniclers and historians note, is that the youngest prince of the House of Nolofinwë died in this battle. Arakáno, son of Nolofinwë, died in the battle of the Lammoth. Indeed, his death is usually the only one noted by name; the rest of the dead are shoved off into the section labeled under 'and many others were slain this day,' their names and deeds and lives forgotten. To most of the chroniclers and historians, Arakáno is the only one who matters enough to be mentioned by name.
But there were others slain this day, with loved ones to mark their passing and mourn for them. They bury their dead, and Márilo is just one of many overturning the earth for someone he loves.
His sword was broken in the battle. Why this happened doesn't matter, only that it did. His sword was broken, but Ilsasírë's was not. She grasped it to the end, fighting for her life until her life was taken from her.
After this day, Márilo always uses his sister's sword. There are many ways to remember the dead, many ways to honor them, and this is his. There are those who look twice when they see him using the sort of sword traditionally made for nissi to use; there are those who question this choice. But they don't know what Márilo knows—that the reflection of a soul can be caught in a sword blade, and memory can give a person strength to face the future.
End Note: See, there's my explanation! A lot of the times in our own world, the roles of women in history tend to be forgotten. Most of our histories were written by men, and in the time periods in which they were written, the impact of women on the world around them was viewed as unimportant. The only way it might be noticed was if it was a very large group of women affecting a very large change, or if a very prominent woman such as a Queen or some other noblewoman was affecting change. Female characters (most of them) have a tenuous enough presence in The Silmarillion that I suspect it to be the same in that world. So chroniclers might reasonably overlook the fact that (noting that this fact is restricted to my head canon) swords made for Noldorin women were curved; what I picture happening also is that, after the First Age had passed, curved swords, for the most part, stopped being made altogether, so that might have contributed to their fall into obscurity.
Turukáno—Turgon
Nolofinwë—Fingolfin
Arakáno—Argon
Nís—woman (plural: nissi)
Falmari—those among the Teleri who completed the journey to Aman; the name is derived from the Quenya falma, '[crested] wave.'
Neri—men (singular: nér)
Endóre—Middle-Earth (Quenya)
Rána—the Exilic term for the Moon, signifying 'The Wanderer' (Quenya)
Vása—the Exilic term for the Sun, signifying 'The Consumer' (Quenya)