This is absolutely astonishing use of light.
The only thing that I would “fix” is the pupils of the eyes – specifically, her left eye. The right eye looks okay, but the left one doesn’t seem to track it and, well, looks a bit diseased. Obviously not what you intended, and very quickly fixed.
Otherwise, it is an arrestingly beautiful portrait which conveys a person in a single glance – and makes her seem noble. The use of two different colors of high-key light, one on the left side of her body (and, neckpiece), and another on the right, is extremely creative, and it works.
If this was a portrait or a visualization of one of your ancestors, you did great honor to her, or to her memory. She does look like a Queen.
(Possibly after a slight re-touching of the eye), I would like to see this image immediately go to The Gallery.