1791 Princess Louise Auguste of Denmark by Anton Graff (Rosenborg Sløt, Kobenhavn Denmark)
This is a dark picture from
which little additional detail can be found. Her life is a study in dynastic
peccadilloes and manouvering. Her Wikipedia article is here.
She was Queen Caroline Mathilde's daughter by Johann Friedrich Struensee,
not the King, but treated as a full Danish Princess. Her daughter Caroline
Amalie became Queen of Denmark.