"From the crown to the toe, top-full Of direst cruelty"

So, we are reading Macbeth by William Shakespeare. Lady Macbeth is amazing. Like wow. So, she gets a note from Macbeth telling her about how he was promoted and there were some weird witches who vanished into thin air. He explained to her that the witches called him three things; Thane of Glamis, Thane of Cawdor, and King. Then when he became the Thane of Cawdor, he was wowed by the fact that the witches had predicted the future, but us as the readers know that it was indeed the present. He writes to his wife telling her that if they witches did predict the future, he might become king as well. Lady Macbeth knows that with royalty, the only way to become the king is be heir to the throne or kill the king and his heirs and be the highest standing person after the king. Well, Lady Macbeth was aware that her husband is too kind and humble to overthrow the king. So she says "from the crown to the toe, top-full of direst cruelty," which is her basically saying that she needs to throw away all of her old self and create a new one. An evil one. One that has no problem will killing the king. One that will slay everyone so that Macbeth will be come the King of Scotland. She needs to act in place of her husband so that her husband gets the crown. She is filling herself with pure evil, and greed is driving it. Greed and her love for her husband. She wants her husband to move up on the social/royal scale so she is doing everything she can do to make it happen. If this isn't a great wife I don't know what is.