Final answer:
Lady Macbeth feels deeply guilty about the murder.
Step-by-step explanation:
These lines suggest that Lady Macbeth feels deeply guilty about the murder.
The lines 'but I shame To wear a heart so white' indicate that Lady Macbeth is feeling remorse and shame for the evil deed she and Macbeth committed.
The phrase 'wear a heart so white' implies that she cannot hide her guilt and is ashamed to have a heart that is not stained with blood. This shows that Lady Macbeth is burdened by her actions and feels deeply remorseful for the murder.