Lady Macbeth's cold hearted side again shows, saying she would 'dash' out the brains of her own child because she is so sure Macbeth should kill Duncan. We also see how Lady Macbeth's influence has rubbed off on Macbeth, as he says 'False face must hide what the false heart doth know', which is very similar to Lady Macbeth's words of the 'innocent flower' earlier. All in all, in act 1 we see how Lady Macbeth has a power over Macbeth, she is cunning and calculated, and despite the fact that Macbeth is the seasoned warrior, she is the one who laughs at murder and Macbeth who declines, however we see her exert her power over Macbeth to make him want to murder Duncan, showing how the power in the relationship is all in Lady Macbeth's court in the first act.
In act two, after murdering Duncan, Macbeth says 'This is a sorry sight', but Lady Macbeth again shows her power over Macbeth. 'A foolish thing to say a sorry sight'. This shows how she is still cold hearted, as she thinks it is 'foolish' for a man to show remorse at a murder he committed. She orders him to not think 'so deeply', saying that thinking about the deed 'will make us mad' and 'unbend your noble strength'. Here we see a slightly weaker side to Lady Macbeth, she is herself feeling vulnerable to guilt, almost immediately after the murder. This is shown in 'will make us mad'. The 'us' shows that she is no longer only concerned for Macbeth, but is worried about her own mental state too, fretting that she may go mad with guilt. But soon after, Lady Macbeth regains her control, and begins to once more organise affairs, 'go get some water and wash this filthy witness from your hand'. This implies that Lady Macbeth wants Macbeth to get dispose of himself, as she asks him to dispose of 'this filthy witness', suggesting that Macbeth rid himself of the part of him that was uncertain and stood watching the other side of him murder Duncan.
