Who is Anna Katarina von Steiner/Catherine Blake from The Unlikely Spy and what is their importance?

Anna was born in London to an English mother and a German father. Her mother died when she was very young, and Anna began devoting her life to pleasing her father. When Anna was a young teenager, she was raped by a poacher on her father's land in Germany. She never told anyone of this event, but it shaped her life forever.