In fairness (waving my girl/girl competitor flag) same-sex Latin is often styled like that. There's a big emphasis on matching (or reflected) hair/make-up/dresses. I know a couple who dye their hair so they looked more similar!
Ballroom can be like that, or you can put the lead in a matching but black dress, or a black stoned leotard and trousers. I have seen one girl who danced in a velvet smoking jacket type thing, which looked really good. Tails on a girl don't really look right — I suspect because they're cut for men the lengths are all off and they don't fit across the boobs.
I think if Nicola and Katya alternated ballroom and Latin it would work better — there's be more contrast. Quickstep and jive are quite similar in character, and couples choice is an abomination not really comparable. She needs a waltz or foxtrot next in my opinion.