In Act 2, What is the significance of Nora's remarks to the children's nurse about the fact that she can't be with them as much anymore?

Nora asks her how the Nurse could have felt comfortable leaving her own children among strangers when she first came to nurse Nora, when Nora was only a child. The Nurse replies that she was grateful for such a good position and that, given her financial situation, she could not pass up the opportunity.

Act I set up the initial invasion of reality into Nora’s world and the first disruptions to the basic underpinnings of Nora’s life. Her assumption of the roles of wife and mother seemed comfortable enough even if the roles rested on fragile premises. Act II eventually sees Nora set up a test that will determine whether or not her domestic world is false to her basic nature.