Lady Macbeth, one of the main characters in Shakespeare's tragic play Macbeth, wishes for the same things as others of nobility: power.
As soon as Lady Macbeth finds out about the prophecies through a letter from her husband, she begins to plot ways through which she and her husband can claim the throne. Fearful that her husband is not "man enough" to take the throne, Lady Macbeth evokes spirits to "unsex" her in order to make her cruel enough to do what needs to be done (murder the current king, Duncan).
Lady Macbeth is simply driven by her desire to be powerful. By Macbeth possessing the throne, Lady Macbeth would possess a certain power of her own. She, just as driven by ambition as Macbeth is, fails to allow "chance [to] crown" her husband.