Was Lady Macbeth filled with evil after reading that letter, or was she always secretly dark on the inside, and it took something like Macbeth being promised the kingdom, to bring it out? Either way, the whole phrasing of that quote was pretty creepy. And also, notice how they didn't say from "head" to the toe, but rather "crown" which has some significance since she's about to hint that she's going to kill the king for his crown.
I feel like she also might be part witch. Because this play so far has been showing that all witches are evil. So by transitive property, since she is so completely filled with evil, she must be a witch. And Macbeth married to a witch is BAD NEWS.
