It's rather odd that Perili has both a summer outfit and a christmas outfit and yet her winter wear is currently available in the middle of the summer, but since I gave Reina some holiday outfits I'll take the chance to get this for her while I can. Hopefully this makes her feel better.
I'm not sure how effective it would actually be at keeping someone warm in the middle of the winter, though. But given she's got a good dense layer of feathers she seems like she'll do fine.