In the vision, not much of her appearance is described. Ella notices nothing except her auburn hair. Though her hair slowly turns gray as the years go by.
Celwe was a carefree spirit as a teenager. It didn't matter to her that she didn't have Legacies and powers like other Loric did.
We see her from time to time in Chapter Twenty in The Fate of Ten. She's first seen dancing on a beach on Lorien, celebrating the two moons by dancing on the shore, surrounded by others drinking and playing instruments. She's watched by a young Pittacus Lore and a young, love-struck Setrákus Ra. Setrákus Ra was too shy to say anything that night, yet she still ended up becoming his bride.
Years pass and we see her again when Pittacus rushes into her house and into the bedroom to find her gazing out the window, hugging herself. The room, as well as the house, is wrecked by the aftermath of her fight with Setrákus. When Pittacus consults her, she tells him about Setrákus Ra's project in the canyon. Pittacus then flies off to put a stop to his plans.
More years pass, and we see Pittacus Lore in the canyon where Setrákus Ra's project was held. But when he's approached by a Mogadorian ship, Celwe steps out to reveal that her and Setrákus have been staying on Mogadore. She then introduces him to her daughter, Parrwyn. Pittacus arranges them a place to stay and to keep them safe.