they don’t look like they’re in their late 30’s

Aren't they around their early 30's?
Sasya's two years older than Karel. Sasya said he was 31yo and he would have only like two years left of professional dancing (by the point he got Charles). 8 years had passed since they first met when they rejoined. Not much time has passed from then til the end maybe a two or three years? Considering mansions take time to build, travelling, settling down, the passing ballet seasons etc.