Is that Princess Ann behind the Queen? How did she become a naval officer?
Yes, that Princess Anne. Her rank in the Royal Navy is honorary.
One might say she was born to it.
Honorary military appointment of Admiral and Chief Commandant for Women in the Royal Navy.
Princess Anne holds several honorary military appointments in the forces of the UK and the Commonwealth, including as Admiral and Chief Commandant for Women in the Royal Navy, and Commodore-in-Chief of HMNB Portsmouth. I would guess without any gret study of the uniform that it is probably the second of these appointments she would have been exercising, if that is in fact her in the picture.