for the fic game: Arwen can see dead people! Well... she can see eight dead people! (Or that one where Arwen can see the Feanor and his sons)
Oh I would write this in a full fairy tale style I think. Arwen Undómiel and her eight ghosts that follow her around telling her stories, protecting her from harm, and giving snarky commentary throughout her life.
It starts when she's very little (at least from what she can remember), she's playing by a stream in the forest and a strange person with silver hair is teaching her how to call out to the birds. He seems nice, even though he keeps his distance, and he promises to give her some archery lessons when she's a bit older.
Then there's the one with the freckles who is always there to comment on what her sewing teachers get wrong (a lot apparently), and who guides her hand when her stitches get a little crooked. It's obvious how fond of her he is, even when sighs in frustrating (which is often). He also tells her stories. Her favorite is of the woman with steel in her veins and a tongue sharp enough to make the most dangerous of warriors blush! He gets a little quiet when telling that one sometimes, and centuries later he congratulates her on her wedding day and she could swear she'd never seen him smile so brightly before.
The twins are her favorite playmates when she's young (and when she's older too, they get up to so much mischief even when she's queen of Gondor). She used to be jealous of her brothers for being such a matched set (and it didn't help that they liked to do everything together), so this felt like getting a second set of brothers that would pay attention to her. And they're the ones that listen best when she's arguing with her parents, or worrying about whether Estel likes her the same way she likes him or not, and even during the war they stay by her side and make sure she has someone to talk to.
There are two dark haired ones who keep criticizing the smiths in Imladris, and they also keep rolling their eyes at Elrond's insistence she cannot have a sword (Elrond had barely wanted his sons to take up the sword, Glorfindel had taught them behind his back. Much like those two ghosts will teach Arwen. Yes, there's something about habits being hard to break and the cycle of violence). Though that's not the only thing they teach her. Arwen's talent for winning every game of Arda Scrabble is notorious and a little scary.
The redheaded one with all the scars is far more distant than the rest. He keeps watch over the roads when she travels, and stands guard by the door of whatever room she's in. But when she's crying or has a nightmare, he sits by her said and braids her hair. Sometimes he calls her granddaughter.
(I lied when I said it was eight ghosts. But two years after her coronation a bard comes asking for work at the court. He never takes his hood or his gloves off, but his songs are the loveliest things anyone born in the last two ages ever heard. Awfully familiar too, sometimes Arwen could almost swear they were lullabies from her youth)