Lady Macbeth's Character

Lady Macbeth starts out as a strong character; she seeks power. Though it would appear she seeks power more for herself than Macbeth, "Whiles I stood rapt in the wonder of it.." and, " When I burned in desire to question them further.." she appears more infatuated with what power she'd hold if Macbeth becomes king more than the power he would wield. She struggles in the beginning to believe the sisters of their prophecy, "The illness should attend it. What thou wouldst highly, That wouldst thou holily; wouldst not play false, And yet wouldst wrongly win.." yet whether or not the sisters are true, she's fully aware of what must be done, and shows now remorse of that knowledge, ""Thus thou must do, if thou have it.. And chastise with the valor
of my tongue, All that impedes thee from the golden round.." she would do what must be done in order to get the crown. Upon the arrival of Duncan, Lady Macbeth asks that her compassion and sympathy be taken away from her so she may complete this task, "Make thick my blood, Stop up the access and passage to remorse, That no compunctious visitings of nature, Shake my fell purpose.." which gives you insight into the depths of her character; she doesn't want to do this deep down, so she must rid herself of her feelings to do this with Macbeth.
You see her compassion is swept away in her conversation with Macbeth, "bear welcome in your eye, Your hand, your tongue: look like the innocent flower, But be the serpent under't.." even with her encouragement towards Macbeth, she lets him know he doesn't have to carry the fatal hand alone, "Only look up clear; To alter favor ever is to fear: Leave all the rest to me." she's showing she'll carry the weight of the burden if she has
to. After Duncan is in the castle, Lady Macbeth has a talk with Macbeth, who no longer wishes to fufill the dead; this irritates her, "Wouldst thou have that, Which thou esteem'st the ornament of life, And live a coward in thine own esteem.." she cannot fathom why her husband suddenly is without the gaul to kill Duncan, which he agreed to do earlier in the play. Near the end of their conversation together, you can tell that the power-hungry side of her is coming out when she presents killing Duncan as, "this enterprise to me?" You can see that she is still in it for her own gain rather than Macbeths. You really see her compassion dissipate when Macbeth comes back with the daggers, and she thinks him a childish fool for feeling guilty, "the sleeping and the dead, Are but as pictures: 'tis the eye of childhood, That fears a painted devil."
After the death of King Duncan, Lady Macbeth starts to be subconciously haunted by the memory of her bloody hands, making her sleep-walk and recite the memory, "Yet who would have thought the old man to have had so much blood in him?" In the memory being recited, you can she she's not only irritated but bothered by the notion of having to kill more people, "What, will these hands ne'er be clean?" Finally in the end, Lady Macbeth is fraught with madness in her sleep and waking life; forever reminded of what she and Macbeth had done.
It is believed that she died in the madness of her
sleep.
All in all, while Lady Macbeth was strong and powerful, her demeanor was really to cover what was truly going on in her head. She didn't want to do this dead, yet tried to rid herself of emotions. She didn't want to plant evidence, but she did it so Macbeth didn't look guilty. All the madness finally caught upto her after Duncans death; her guilt and emotions had hit her in full swing, causing her to drift into sleepwalking and finally, death.