Who is Yanka from Russka: The Novel of Russia and what is their importance?

Yanka is only seven when the Tatars attack her village. Afterward, she flees the village with her father and move to Murom, where her father will find work on Milei's estate. She later becomes Milei's mistress and goes onto marry a man named Purgus. In the novel's conclusion, Yanka recognizes the man who killed her mother during the Tatar attack and shoots him with an arrow.