We often talk about Azriel’s striking looks. The prettiest of the three brothers. But what about Gwyn ? Let’s start off with the necklace as it is canonically, Gwyn’s parallel.
We see a nod to the necklace’s description in acosf when Nesta was momentarily taken aback by Gwyn’s beauty. It’s not just that Gwyn is described as pretty. It’s how people begin to see her that changes. Nesta starts off with a more subtle description, then later says Gwyn rivals Mor and Merrill, who are basically the top-tier beauties in the series. That kind of comparison is never made lightly in this world. SJM is putting Gwyn in the same league as the women the narrative already treats as the most beautiful.
That’s a very different approach to how the Archeron sisters are described. Their looks are almost always defined through comparisons to each other. Feyre is plain next to Elain. Nesta is striking and is the only sister who isn't flat chested. Elain is the classic beauty. It’s all relative. But with Gwyn, she’s not being contrasted against someone else. She’s placed next to characters like Mor as an equal. Her beauty stands on its own and grows as she gains confidence.
Even Az makes a comment about how he’s noticed Gwyn has changed in the BC. Besides thinking how far she has come since that day in Sangravah and her charming irreverence, he also notices the way her freckles crinkle on her nose, how her hair shines like molten metal, and by the end of the chapter, he’s still thinking about how her eyes would light up. I’m just saying, he’s starting to pay attention to her appearance in a different way. Seems like a (slowburn) foreshadowing buildup to the classic mate line : ‘she’s the most beautiful female he’s ever seen’. Also just to say the shallow thing, SJM likes to make her main characters hot, so just saying.
As far as her beauty goes, I've always imagined Gwyn as someone who has this ethereal beauty to her that shines the more she comes out of her shell. Just think about it. She's fae and a nymph. A redhead with beautiful mix of blue-green eyes and years of yoga practice. And to top it all, the acolyte training includes grooming them in the art of seduction too. (Funnily, gwyn’s non-priestess nymph grandma seduced a high fae lol so that’s two layers of seduction built in her). All that beauty, litheness and grace from all sides rolled into one person. She has to be a beauty to rival the top beauties. I don't even want to be subtle about it tbh. Yes, I'm crowing about how pretty she is here and shamelessly singing her praises. She's a brave, kind, smart, tenacious, loyal and ethereal looking beauty, and this is all based on textual evidence from a single book. SJM sure has favourites. Can Az fight?
‘Or maybe nothing at all had changed beyond that confidence, the way Gwyn's shoulders were pushed back, her head held high, her smile free as she said, "Roslin. Dierdre. Ananke. I was hoping you'd come."
I think this spells out perfectly what SJM is illustrating with the heightening of Gwyn's heavily detailed beauty. It's a theme that with self-acceptance, self confidence comes the best version of oneself. She's illustrating that Gwyn is already on her healing journey and the Valkyrie training fuelled it even more, allowing others to see the beauty she had all along. A thing of secret, lovely beauty, indeed.
(I found this on gwynriel reddit recently, and added bits and pieces of my take inside it)