Shakespeare uses several symbols in Macbeth to indicate either the guilt or innocence of a character. The major symbols of guilt are blood and sleep. When a character has blood on their hands this is an indication of their guilt. The blood can either be literal (actually there) or figurative (imagined or implied). Also, when a character is unable to sleep, the audience can assume they are guilty of something. Shakespeare uses sleep as a reward for the innocent. Think about it, it’s hard to sleep when you are bothered by something. You keep thinking about it!
If you will think back to Act V, when Lady Macbeth is sleep walking and imagining the blood on her hands, this is twice a symbol of her guilt. She is not actually sleeping ( a reward for the innocent), and she is struggling to wash blood (a symbol of guilt) off her hands. If you examine the text and look for images dealing with blood and sleep, you will soon be able to collect your quotes addressing her guilt.