Her part is decisive. If you read or watch Act 1 Scene 7 you will know that Macbeth, left on his own, decided not to commit the murder. He says "We shall proceed no further in this business." Lady Macbeth then proceeds to change his mind, at least for long enough that the deed gets done. She appeals to his irrational emotions, when his decision not to commit the murder was based on reason and logic, as shown in Macbeth's speech, "If it were done when 'tis done, then 'twere well it were done quickly."
Lady Macbeth plays a significant role in influencing Macbeth to kill the king by questioning his masculinity and manipulating his ambition. She encourages him to act on his desires, planting the idea in his mind and pushing him to carry out the murder to fulfill their ambitions. Her ambition and determination drive Macbeth to commit the heinous act.
The witches show Macbeth a procession of Banquo's descendants as kings.
Macbeth is King Duncan's cousin as well as a general of the king. Later into the play, he becomes king.
Macbeth kills Duncan in his own castle at night time.
Macbeth tells Lady Macbeth that he has decided not to go through with the plan to kill King Duncan.
At the end of the play Macduff gave Macbeth two choices; surrender and live under the rightful king of Scotland or die. Macbeth chose death.
Duncan shows his affection for the Macbeths by giving them gifts. In particular he gives Lady M a jewel.
She tells him that he has to die so MacBeth can become king.
Macbeth was the Thane of Glamis and one of Duncans generals. After killing Macdonwald, Macbeth became the Thane of Cawdor, and later the King of Scotland (after killing the king)
Lady Macbeth advised Macbeth to ignore his conscience and continue with their plan to kill King Duncan, even if he could not say amen after his prayers. She believed that their ambition was more important than moral guilt.
The crucial part. Without Lady Macbeth, this would have been Macbeth's final decision: "We will proceed no further in this business." Macbeth would never have killed Duncan unless Lady Macbeth had goaded him into it.
Lady M is all for it but Macbeth is unsure and has to be pushed into doing it. He then immediately regrets it.
NO! Lady Macbeth does not kill king Duncan's Guard Macbeth does to prove his guilt.