The queen, Duncan’s wife and Malcolm and Donalbain’s mother, is dead.
Although there is a king at the beginning of the play, there is no mention of the queen. Malcolm and Donalbain obviously had a mother. However, the first time a living queen appears is when Macbeth and Lady and Macbeth enter after killing Duncan in Act 3, Scene 1, and Lady Macbeth is described as the queen.
The first actual appearance of the “queen” that would have been Duncan’s wife is when Macduff is discussing the retaking of the kingdom with Malcolm. Here he mentions Malcolm’s mother.
Basically, Macduff is saying that Malcolm’s mother is dead (she is spoken of in the past tense). He describes her as virtuous, and always praying. Macduff considers both Duncan and Lady Duncan more virtuous than the Macbeths.
There is no sitting queen when Macbeth kills Duncan, but at that point Lady Macbeth becomes the queen. She is not spoken of in such high terms by Macduff, who calls her the “fiend-like queen” (Act 5, Scene 8). She spends most of her time offstage once Macbeth becomes king, until she kills herself. At this point, all we hear is that she is dead.
The one appearance Lady Macbeth does make shows her wracked with guilt about killing Duncan. She wanted to be queen, and wanted Macbeth to be king, but once in that role she seems to have experienced more and more doubt. This finally leads to her breakdown.
Out, damned spot! out, I say!--One: two: why,
then, 'tis time to do't.--Hell is murky!--Fie, my
lord, fie! a soldier, and afeard? What need we
fear who knows it, when none can call our power to
account?--Yet who would have thought the old man
to have had so much blood in him. (Act 5, Scene 1)
Lady Macbeth realized after the fact that their actions were wrong and the situation was precarious. She fears that they will go to Hell for what they have done. As it becomes more and more obvious that they are going to lose, she finally takes her own life.
Although she never is alive during the play, Shakespeare takes the time to provide a clear contrast between Lady Duncan and Lady Macbeth. Lady Duncan he describes as being virtuous and worthy, whereas Lady Macbeth is violent and wracked with guilt. When Macbeth learns of his wife’s death, he is deeply saddened and experiences some guilt of his own as he begins to ponder his mortality.