As a 9th grader, you're about the age of Koly when she marries a boy about that age who isn't healthy. Then Koly discovers that the boy's parents are only interested in the dowry (tradition of parents of the bride giving objects of value to the groom's parents), so it can be used to save their son's life. Then Koly's husband dies. How would you feel as a new bride of thirteen whose husband dies soon after the marriage?
The death of her new husband begins the next stage of Koly's nightmare. She's not allowed to go back to her parents. Indian custom requires her to stay with her in-laws. Now, she must stay with people she hardly knows and endure the insults and criticism of her mother-in-law. At this point, she's not grieving for her husband, but for the life she's never had, or will ever have, a chance to live. The only comfort she finds is with Chandra, her sister-in-law, but then Chandra marries and leaves home. Her hope for some kind of future fades again.
The main conflict of the story is within Koly herself. She struggles with what is expected of her as a young, widowed woman in a very traditional society and what she wants her future to be, her own dreams of happiness. You'll learn as you experience more adversities in life that literally "what doesn't kill you makes you stronger", and this is what happens with Koly. She could have become one of many white sari-clad widows chanting in the temples and fighting to survive, but Koly finds the courage to fight for what she wants, even if it means going against years of tradition.
As Koly matures, she meets other people who help her learn to become independent. She goes from being a homeless child (a bird) to being a career woman. She takes responsibility for her own life.