Nora's changes relate largely to the development of her ability to be honest, independent and self-determined.
Initially, Nora is seen sneaking macaroons when Torvald cannot see her. Keeping this secret shows that she is, to some extent, willing to be subservient to Torvald. She will not follow all of his orders, but she also will not openly break his rules.
Quotes relating to Nora's attempts at secrecy are present in Nora's first discussion with Mrs. Linde.
Later Nora continues to expect Torvald to save her from the predicament with Krogstad. She is dependent on his good will and hopes for a "miracle". When this miracle is not forthcoming and Torvald's response to discovering Nora's situation is a selfish one, Nora finally forces herself to the realization that she must learn to depend on herself. She must develop her own opinions.
She no longer keeps her feelings secret after her trouble with Krogstad is aired. Instead, she boldly confronts Torvald and begins to make her own demands and to dictate how things will change.
Here, in the final act, Nora characterizes the situation instead of allowing it to be characterized for her (or to be characterized by it):
Nora claims, “You never loved me. You just enjoyed being in love with me.”
Her new attitude indicates the great change that has taken place in her, which leads her to leave her husband and children so that she can develop as an individual. No longer meek, she is now assertive.
"It's almost a miracle" (Nora,act one)
In Act 1, Nora is still in a child's fantasy and a unrealistic dream. She believes that society is forgiving, and that Torvald (after learning that she has borrowed money to save him and keep the family together) will pay off all her debts, and Torvald will love her more. She is believes that her forging her father's signiture is fine, and the law will not blame her for it. When Krogstad states that the law ‘takes no account of motives’ and Nora believes that the laws ‘must some very bad’ ones. We can see she is naive and she has been protected from the world, first by her father, and now by her husband.
"I no longer believe in miracles" (Nora, act three).In the final Act, Nora leaves the role of the doll she played her whole life, and becomes an adult. She realizes that the world is different than she always thought it was, and that she herself is not who she thinks she is. When Nora tells him of the whole story, she is shocked to see her husband's reaction. Then she realizes that while so busy doing tricks for him in order to make please him, she never really got to know the real Torvald. She tells him that: " I'm saying that we've never sat down seriously together and tried to get to the bottom of things". Her final discovery, that she had been living with a man who she has never known, and that she does not know herself at all, is the main motive for leaving her house & not believing in the miracles.