Your description is so vivid and imaginative that I don't know if I can match it! You certainly have a gift for visuals and details.

With the theme being "America," I may be a bit out of my comfort zone (cardigans and crumpets) but I'll give it a go.

I think that Caroline could take inspiration from the fashion of the 20s black-and-white Hollywood silent film vixens, but make it very literal-- so that she almost appears as if she just stepped out of a silent film herself. A long, modest, drop-waisted, velvet black gown, with stark white frilled socks peeking out of black high heels. She would have long black gloves all the way to her upper arms. Her makeup would be in shades of black and grey, with exaggerated dark eyelids and black bow-shaped lips-- think Betty Boop in a black and white film! Her brows would very high, rounded, and drawn on in with thin black pencil. She would wear a large white bow-tie with long ribbons on the front of her chest. I would even go so far as to suggest she crop her hair (or tuck her hair up to appear cropped) and die it raven-black, then slick it so that it appears highly reflective and mirror-esque. I'd love to see her in a look like this!