How does Hannah/Chaya change emotionally/mentally throughout the book?

Over the course of the novel, Hannah Stern, the novel's protagonist, transforms from a teenager who is disinterested and even embarrassed by her Jewish heritage, into a young woman who learns to appreciate the heritage and history of her family.

When we first meet Hannah, she is on her way to a family gathering, a Seder dinner, which is a tradition in the Jewish religion. She has no desire to go, and she is bored by the entire event. Boredom aside, she does take part in the Seder and is somehow transported to Poland in 1942. While inhabiting the body of a distant relative, Hannah comes to experience the reality of the Holocaust, and during the experience, she becomes a caring, compassionate, and self-sacrificing, young woman.