Before we pay attention to the similarities between Lady Macbeth and Lady Macduff, we must point out that these two women stand in stark contrast to each other. Lady Macbeth is cruel, manipulative, and active as opposed to Lady Macduff who is caring, innocent and passive. For instance, Lady Macbeth's statement that she would dash "the brains out" of her child if that was necessary to show that she can keep her word is in sharp contrast with Lady Macduff's playful arguments with her child about Macduff's lack of care.
However, we can notice some similarities between the two women. Firstly, they can both be viewed as atypical women in the society they live in because they both admonish their husbands and, therefore, criticize the concept of patriarchy. Lady Macduff openly reproves her husband for leaving his family unprotected:
He loves us not;
He wants the natural touch...
She cannot understand why he would leave them all, and she criticizes her husband in front of Ross.
Lady Macbeth reproves her husband for being afraid to keep his word and kill Duncan. She encourages her husband to act like a man and not like a coward, inviting him to display the characteristics of masculinity:
Wouldst thou have that
Which thou esteem'st the ornament of life,
And live a coward in thine own esteem,
Letting 'I dare not' wait upon 'I would,'
Like the poor cat i' the adage?
Secondly and lastly, another similarity between Lady Macbeth and Lady Macduff lies in the fact that they both die because of their husband's actions. Lady Macduff dies because her husband has to leave and she is left unprotected. Lady Macbeth dies as a result of her repressed guilt and the lack of her husband's care. Towards the end of the play, Macbeth withdraws into his own world, leaving his wife vulnerable and victimized by her guilt, which arises from all the horrendous deeds they committed together.