Andrei's younger sister, Marya, is terrorized by her father and becomes a deeply religious and self-doubting woman.
So how do you solve a problem like Marya? Apparently all it takes is one fairy-tale rescue from a man on a white horse and she turns into an awesome wife and mother. (Warning: do not try this at home.) As with most of the other characters who transform in the novel, all it really takes is a change of circumstances – or a series of gradually shifting circumstances.
When you read about Marya, it's always a good idea to keep a mental tab of how many people are controlling her life. Shmoop would argue that she comes into her own as the restrictions on her behavior are gradually lifted. When her father lords it over her, Marya pretty much accepts her lowly status. Her big dream is to run away and become a traveling "person of God" – basically a religious beggar who has given up all worldly life. There's no there there with her at this point – she's just a ball of fear and anxiety.
But as life makes her more and more free, and more and more in charge (she starts raising her brother's son, her father is incapacitated, she inherits a vast estate after her father and brother die), Marya becomes confident and a lot more normal with her emotions. Eventually, she knows what she wants (to marry Nikolai Rostov) and goes after it. At the end of the novel, we find her a good wife and mother.