In "A Doll's House", Torvald makes a comment concerning Nora's management of money. Why is this comment ironic?
Yes - he calls her a "spendthrift", and metes out the household money to her from his own pocket, rather stingily.
The irony comes simply because Nora is, in fact, an extremely skilful manager of money. What Torvald is unaware of is that she, long before the play began, organised a loan of enough money to take her husband abroad, in order to save his life. Torvald never knew of this loan, and Nora has been working in secret to pay it off for years, forging her father's signature in order to secure it.
Though Torvald treats her like a "doll", Ibsen makes it quite clear that she is an adult perfectly capable of dealing with responsibility.