Final answer:
Lady Macbeth's inability to kill King Duncan is not due to a soft side, but because he reminded her of her father. Her character is marked by ambition and manipulation rather than compassion, and her hesitance comes from a personal association.
Step-by-step explanation:
The statement that Lady Macbeth couldn't kill King Duncan herself and it being the first time we see her "soft side" is false. The character of Lady Macbeth is complex, and her inability to commit the murder is not due to weakness or a soft side. Instead, in Act II, Scene II of Shakespeare's Macbeth, Lady Macbeth explains that she could not kill Duncan herself because he resembled her father as he slept, which shows her hesitation is based on a specific personal association rather than general compassion or softness.
Throughout the play, Lady Macbeth exhibits a ruthlessly ambitious nature and plays a crucial role in persuading Macbeth to murder Duncan. She challenges Macbeth's manhood, questions his love, and takes charge after the murder by attempting to cover up the crime. It's her growing guilt and eventual descent into madness that reveal vulnerability, not an inherent softness.