Why does Nora abandon her children in A Doll's House?
I'm not sure "abandon" is the right word for Nora's actions--we ultimately don't know whether Nora restores a relationship with her children after leaving Torvald or not. Nora does leave her husband at the end of Act III after she is forced to face his true nature and realizes how selfish he is. She also realizes that, as Torvald's wife, she has lived more of a child's life than an adult's. After her confrontation with Torvald, she most wants to reeducate herself to live as an independent woman. About her role as a mother, Nora says to Torvald:
"I am not fit for the task. There is another task I must undertake first. I must try and educate myself--you are not the man to help me in that. I must do that for myself. And that is why I am going to leave you now."
Nora's decision is not so much to abandon her children as it is to put herself first for the first time in her life. In addition to motherhood, Nora believes that:
"I have other duties just as sacred. . . duties to myself. I believe that before all else I am a reasonable human being . . . or, at all events, that I must try and become one."
When Nora leaves her home at the end of the book, she leaves her children because she knows that they will be better off with their father. She is going into an unknown situation, she has no job and no income or a place to live when she leaves. Therefore, leaving her children is a sacrifice, because she does love them, but it is because she loves them that she won't subject them to the harshness of life outside of their father's house.
I also feel that Torvald would not have let Nora take his children. It is one thing for a woman to leave her husband, but the type of man that Torvald is suggests that he would not have allowed Nora to take his children out of the house. The children will continue to be cared for by a Nanny, who, Nora feels at this time, is a better mother than she is in her present state of mind.
I agree with the statements above.
If you would look at the situation and see Nora as a bit selfish, you could argue that leaving her children gave her the liberty to start a new life and in some ways, to "grow up". Living with Torvald kept her from learning the things she needed to. However much she loves her children, maybe leaving them was important. Her children are what connects her to her husband. Leaving them would allow her to have a fresh start.
I don't think that these were her reasons, but its a different form of interpretation.