I think the name Dutchess is VERY fitting. She has a very regal attitude.
Don't stress out over posing her. It may take time to practice with her, to get her used to sitting that way. (Sorry, the Stifle joint is their knee.) It's good to do with her before the shows so she behaves for the judge. It's cute when a tiny little mini rex won't pose, it's a pain in the neck when an 11+ lb Flemish won't pose.
If I could get shoulders like that on my blues, I'd be SO happy!