Do you think the characterization of Nora changes? Is she child-like, or is she something more?

Yes, Nora's character definitely changes during the course of the play. At first, she is rather childish, accepting pet names from her husband—names like "squirrel" and "little bird"—diminutive terms that seem to stem from and describe her lack of maturity. In addition, her husband has forbidden her to eat sweets so they don't rot her teeth, and so she merely hides them from him like a small child who is disobeying a parent. By the end of the play, however, Nora has matured a great deal. She realizes that, to both her father and her husband, she has been like a toy. She says, of her father, to her husband Torvald

He used to call me his doll-child, and played with me as I played with my dolls. Then I came to live in your house . . . . I mean I passed from father's hands into yours. You arranged everything according to your taste; and I got the same tastes as you; or I pretended to—I don't know which —both ways, perhaps . . . . I lived by performing tricks for you, Torvald. But you would have it so.

Nora realizes that she has not been truly loved for herself, but because she acted the way the men in her life wanted her to—as an obedient and compliant child. Now, however, she refuses to be anyone's doll, and she abandons her family in order to acquire the "perfect freedom" from expectation that she now desires.