When she stands up to follow the soldier she realizes that Dressing Room has totally redone her outfit.
Brenda's armor, while still clearly intended less for ceremony than for combat, is elegantly embossed and polished until it gleams. The clothes underneath are legally and culturally suitable for a non-noble military officer, but one with a massive clothing budget and a very tasteful and intelligent tailor to absorb said budget. The soft green and white fabric drapes in elegant lines that flatter her four-arned figure and draw the eye to follow her movements. The boots are fine leather and hug her calves in a way that makes her legs look longer, with heels thick enough to add a bit to her height but not tastelessly or obviously so; they also encourage her to take longer, more confident strides. Her cloak of resistance, being a magic item, is unchanged, but she's now wearing a second shorter cloak atop it, green embroidered in white and silver with the image of an owl holding a sword*. Her hair has been artfully piled atop her head in a way that reveals the elf ears, deemphasizes the cat ears, and shows off the headband.
Brenda can't actually see all the changes, but she can tell they're extensive. And unlike every previous formal event she's had to dress up for, nothing has poking tags or obtrusive seams or gets in the way of her movements. It feels like Dressing Room cheering her on. She smiles at the queen and everyone else, pleased to see that Rathimus agreed to join. "I'm ready."
*Vert, an owl close guardant maintaining in its talons a sword argent, if you know the jargon and want a clearer mental image. It's not overtly heraldry, it's plausibly deniable, but it's also a design nobody else in Mendev or any nearby country happens to be already using. The narrator is indulging herself.