Nora's relationship to her children is complex. They are a source of joy to her in the first act, but it is clear that Nora's relationship to her children is somewhat distant. The nurse is responsible for the work of caring for them; Nora reserves for herself the joy of playing with them. In fact, Nora's idea ultimate happiness is to be "free from care" and to "play and romp with the children."

At the same time, the children and her family life, form the basis for Nora's understanding of herself. Her decision to borrow money to pay for a therapeutic trip for her husband to "the south" is a kind of secret agency on her part. She can never tell Torvald where the money really came from for the trip, and she secretly takes on copying work to pay back the loan. For Nora, forging her father's signature on the bond seems inconsequential given need of her husband (she tells herself that she did it "for love's sake." Her "love" for her husband is of a piece with "love" for her children: they are both examples of her emotional infantilization.

Her fear for her children, and specifically her fear that her deception about the money might be a bad influence on them, is an important factor in her decision to leave her husband. Torvald's off the cuff remark about Krogstad's deception and how it "poisons the whole life of the home" sets in motion a kind of emotional reckoning for Nora, who eventually comes to see that her married life was that of a "doll wife" and her children had been her dolls.

In Henrik Ibsen's A Doll's House, Nora and Torvald Helmer's three young children serve as a reflection of Nora's place in her marriage and in her home. This symbolic representation is apparent in the first line of the play.

NORA. Hide the Christmas Tree carefully, Helen. Be sure the children do not see it until this evening, when it is dressed. (Act 1)

This is what Torvald does to Nora. He hides things from Nora, patronizingly explaining to her that he's protecting her and that he doesn't wish to worry her about things that he believes she can't understand or can't fully appreciate. Nora loves the children dearly but treats each of them in much the same way that Torvald treats her—like a doll. "My sweet little baby doll!" Nora says to her youngest child. "No, dogs don't bite nice little dolly children," she says to another child.

Ultimately, Nora rebels against being treated like a child and like a doll. She tells Torvald that she's been treated like a doll all of her life.

NORA: When I was at home with papa ... He called me his doll-child, and he played with me just as I used to play with my dolls. (Act 3)

Nora describes her marriage with Torvald like living in a child's playroom.

NORA: I have been your doll-wife, just as at home I was papa's doll-child; and here the children have been my dolls. I thought it great fun when you played with me, just as they thought it great fun when I played with them. That is what our marriage has been, Torvald. (Act 3)

The issue of the children being treated as dolls isn't resolved. Nora leaves the children in the care of their nurse, Anne-Marie, who was also Nora's nurse. In all likelihood, the children will be raised as Torvald wants them to be raised, as little doll-children, just like Nora was raised and just like Torvald treated his "doll-wife."

The children are precious to Nora. They are also her figurative counter-part, representing a mode of being that Nora continues to inhabit as an adult. From the play's opening, we see Nora surreptitiously sneaking cookies like a child.

Her day is filled with constant acts of subterfuge—some minor, like sneaking macaroons, and some of the utmost importance, like paying back a loan that saved her husband’s life.

Symbolically, it is important to note that Nora is most "herself" when she is with her children. By the end of the play, we see that this is true because, like the children, Nora is an unformed person without a true identity of her own. The playful and gratifying time she spends with her children can be viewed as an indication of Nora's state of development. 

Another element of meaning associated with the children comes from Nora's personal history. Nora was raised without a mother figure. She was raised by the same nurse that lives with her during the action of the play, Anne-Marie. This fact impacts Nora in at least two ways.

She is able to leave her children in the end because she will be leaving them with the person who raised her, a competent surrogate mother. This is akin to a realization that children do not need both parents, at least not in an absolute way. 

Though Nora wanted to give her children a loving mother in their lives, something she never had, she ultimately is driven to repeat history and to leave her children without a mother. 

Part of what leads to Nora's decision to leave her children without a mother is the idea that she might corrupt them and ruin their lives. When the idea is planted that Nora's crime of forgery may ruin her children, she begins to fear the worst. 

Torvald voices this opinion when he mentions that people like Krogstad end up with moral deficiencies because a mother has failed in her responsibilities.

In deciding to leave them, we can see this fear as well as her confidence in the abilities of her nurse to raise the children. The children can be seen as Nora's legacy here, and she must decide how to shape that legacy: risk corrupting them by staying in her marriage and remain a child herself or leave them motherless and go off to develop an identity of her own.