How does Lady Macbeth characterize Macbeth who'll she is reading his letter? What does she reveal about herself in this scene?

At Inverness, Lady Macbeth reads a letter from Macbeth that describes his meeting with the witches. She fears that his nature is not ruthless enough-- he's "too full o' th' milk of human kindness” (15)—to murder Duncan and assure the completion of the witches' prophesy. He has ambition enough, she claims, but lacks the gumption to act on it. She then implores him to hurry home so that she can "pour [her] spirits in [his] ear" (24)—in other words, goad him on to the murder he must commit. When a messenger arrives with the news that Duncan is coming, Lady Macbeth calls on the heavenly powers to "unsex me here" and fill her with cruelty, taking from her all natural womanly compassion (39). When Macbeth arrives, she greets him as Glamis and Cawdor and urges him to "look like the innocent flower, / but be the serpent under’t" (63-64). She then says that she will make all the preparations for the king's visit and subsequent murder.

Lady Macbeth sees "remorse" as one of the names for feminine compassion—of which she must rid herself. Thus she must be "unsexed." This does not mean, however, that in rejecting her femininity she becomes manly. Instead, she becomes a woman devoid of the sexual characteristics and sentimentality that make her a woman. She becomes entirely unnatural and inhuman. Like the supernatural Weird Sisters with their beards, Lady Macbeth becomes something that does not fit into the natural world.