I know of two other books which might interest you. The first is 'Elisabeth, Queen of the Belgians' by Sydney Cunliffe Owen. She was the consort of King Albert I. I can't recommend this book enough. I learned so much about this fascinating woman, who was also a trained opthalmologist. She was taught by her father, and was known to walk unaccompanied through the poorer villages, giving visually impared people consultations, and arranging for free surgeries to be performed.
The other book is her husband's biography: 'Albert of Belgium' by Emile Cammaerts. I own this book but haven't read it yet. It's quite heavy and appears to be a more scholarly take on his life.