According to lady macbeth, why doesn’t she kill duncan herself? indicate which lines in the tragedy of macbeth, act ii, pointed you toward your answer.

"Lady Macbeth did not kill Duncan herself because while he was lying there sleeping, he reminded her of her father. She says, "He could not mess 'em. Had he not resembled/my father as he slept. I had done 't" (2.2.1). Lady Macbeth says that she would have killed him, but because he looked like her father she was unable to. "

Explanation:

Change wording.

(She could not kill the sleeping Duncan because in sleep he resembled her father. She expresses this reason in Act II, Scene ii, lines 12-13.)