(Just saw this, sorry!) She generally is pretty dolled up (comes with the job), but she'll of course wear different basic outfits such as swimwear, comfy nightclothes, the usual. She sort of lives in a fantasy environment where modern technology/style isn't around, so she doesn't slip into casual clothes. I'd love to design her some sort of nightgown soon!

She generally wears her royal garb as per tradition though, yeah (she does wish sometimes that they fit better, but that's not up to her, as I mentioned in another answer her dresses have been passed down from generation to generation without being refitted)