In Macbeth, why does lady mcduff tell her son that mcduff is dead?

Question

It takes place in Act 4 Scene 2

Answer 1

I havne't read it in a while.... Maybe he's dead to her, since he left her and her children to fend for themselves.

Answer 2

It's an announcement that the man she knew, the constant husband, the good father, is no longer alive. She's been told that he's fled the nation, leaving her and the children behind. She feels betrayed that he didn't tell her he was going, that he'd flee a danger and leave them to suffer that same danger. So the man she married, the man she trusted enough to have children with, the man the children have grown to know and love, is dead to her, and she determines to make him dead to the children too. Such is the power of her feeling of betrayal and rage. The fact that she and the children are killed soon after acts as a resolving factor in McDuff, but it also sits heavy on his conscience, and her words about him fleeing and leaving them behind are a part of his motivation to remove the evil on the throne of Scotland.

Answer 3

I like Falco's answer posted before this one.

Another interpretation may be that she is just teasing her son. They are having a rather light-hearted conversation, some pleasant banter, and perhaps she is teasing about this subject. Her son sees right through her statement that his father is dead, countering with some clever observations about her behavior.

Of course, this is all ironic considering what is about to happen to this family.