Personally I'd like to see Jasmine with a really miserable cold, she's always been my favourite.
With one detail from me: she looks better (and more prone to having cold) while wearing her default outfit.
And what about Merida? Being not so ladylike that other Princesses, she can be proud of having a loud and dramatic sneeze which will likely make her wild mane to bounce like crazy.
Or Rapunzel. Being so isolated from other people, she may wonder what's the point in suppressing herself when nobody will hear anything and this dust from a bookshell gives her so great tickle?
If you’re going to do more princesses, please examine their modern casual outfits seen in Ralph Breaks The Internet.
Oh, how lovely they are, especially Elsa's pitch black leggings with sparkles (but I personally would more like to see all these girls
sleeping in their lounge room than
sneezing. Ariel's hair look so comfy to use it as a pillow). Aaand... It would be great to hear how Snow White will respond «Bless you, sweetie!» in her singing manner.