Despite the coldness of her resolve, her devious scheming, and her very effective emotional manipulation of her husband, Lady Macbeth, in the final analysis, is merely a woman, not a super woman. The first suggestion that she is not invincible is her reaction to the sleeping King Duncan. She would have killed him herself, she says, except he reminded her of her own father. This suggests that Lady Macbeth, beneath the steel will of her ambition, is not impervious to feeling softer human emotions; it suggests she had loved her father.
This glimpse into her humanity foreshadows her emotional unraveling in Act V when she walks in her sleep, reliving the murders for which she and Macbeth bear responsibility and expressing horror over the blood that has been shed. Despite her earlier displays of emotional strength and control, she has imploded under the weight of fear and guilt. She is a pitiful sight, walking alone in the dark carrying her candle, sighing from the depths of her soul. Unable to bear her pain, Lady Macbeth commits suicide.
Prior to her destruction, she exhibits other traits to suggest that she is no super woman in dealing with her life and circumstances. Although she strives to relieve Macbeth's guilt and fear after Duncan's murder, struggling to keep him sane and functional, she underestimates the depth of his despair and cannot deal with it successfully. Macbeth spins out of control; one murderous action follows another, with Macbeth acting on his own. Lady Macbeth loses control of her husband and her own fate. A super woman might have been able to manage the events she set into motion through planning and manipulating the murder of the king, but Lady Macbeth is not a super woman. She is instead a human being, subject to human weakness, who brings about her own destruction.