Lady Macbeth tells her husband exactly what to do and says he is a coward if he doesn’t do it.
Lady Macbeth is thrilled when she gets a letter suggesting that Macbeth might be promoted to king. She does not seem to wonder about the fact that the witches were the messenger for this. She just goes with it.
In order to convince Macbeth to act, she talks sweetly to him. She tells him exactly what to do.
To beguile the time,
Look like the time; bear welcome in your eye,
Your hand, your tongue; look like the innocent flower,(70)
But be the serpent under't. (Act 1, Scene 5, p. 20)
Macbeth does not seem convinced. At this point, he tells her they will talk about it later. Lady Macbeth won’t take “no” for an answer. She tells him, “Leave all the rest to me.”
When Macbeth decides he doesn’t want to go on, she gets angry and basically calls him a wimp. She seems to indicate that she is more of a man than he.
Art thou afeard
To be the same in thine own act and valor
As thou art in desire? (Act 1, Scene 7, p. 23)
She is asking him if he is afraid to act for his desires. She asks him if he is a coward, too. Then she says she would be willing to nurse a baby and then bash its brains out. When he asks he if they should fail, she scoffs and dismisses him.
But screw your courage to the sticking-place,
And we'll not fail. (Act 1, Scene 7, p. 24)
She is basically telling him that if he can get his act together and not be scared they will succeed. She pushes and pushes until he finally relents. She has convinced him.
Lady Macbeth manipulates Macbeth in a number of ways. She insults him, flirts with him, and prods him on. She basically lays out all of the groundwork, plans everything, and tells him he is a fool and a coward if he doesn't follow it.