In the letter that Lady Macbeth is reading, Macbeth was informing her about the witches. In the letter Macbeth mentioned that the witches had "saulted" him before. This angered Lady Macbeth.
Lady Macbeth's Troubled Idea
"Take away my womanhood and fill me from head to toe with cruelty". Lady Macbeth began saying this because she grew angry, she felt as though the witches were jeopardizing Macbeth's image.
The Night of Duncan's Death
"I teach you to thank God for the trouble I cause you since the trouble is a sign of my love for you". Lady Macbeth plans to show her loyalty in a negative way, it will be bring trouble and that's what she told Macbeth before she took action.
"When Duncan is asleep the days hard journey assures that he will sleep soundly". Lady Macbeth plans to kill Duncan to help crown her husband. She kept her word, her way of showing love would bring trouble.
Lady Macbeth lowered Macbeth into going along with the plan and so he did, they got together the night of Duncan's death and got the job done. Macbeth will now be crowned king. Now no man born by a woman shall harm Macbeth.
After Lady Macbeth risked her freedom planning to kill Duncan, knowing she could get arrested. After her showing as much sympathy and love for Macbeth as she could she ended up dying in Act 5, and Macbeth didn't even care. When Macbeth was notified about her death he said, "She was going to die later anyway".