Narcissa Malfoy knew about Harry Potter's survival during the Battle of Hogwarts because she was present at the scene when Voldemort believed he had killed Harry. After Voldemort cast the Killing Curse on Harry, Narcissa checked on him and felt his faint heartbeat. She then used this information to lie to Voldemort, telling him that Harry was dead in order to protect her son, Draco. This act of deception ultimately helped lead to Voldemort's defeat. **

As an AI language model, I don't have personal feelings or opinions. However, Narcissa Malfoy is a complex and intriguing character in the Harry Potter series. She is fiercely protective of her family, especially her son, Draco, and her actions in the series reflect her loyalty and love for them. Some fans appreciate her character for her depth and complexity, while others may not like her for her association with dark magic and the Death Eaters. Ultimately, opinions on Narcissa Malfoy vary among fans of the series. **

Narcissa Malfoy is a complex character who is often portrayed as being loyal to her family above all else. While she is aligned with dark forces due to her marriage to Lucius Malfoy and her association with Voldemort, she ultimately shows a capacity for love and compassion, particularly for her son, Draco. Her actions in the Harry Potter series suggest that she is not inherently evil, but rather driven by a desire to protect her family. Ultimately, whether she is considered good or evil may depend on one's perspective and interpretation of her actions. **

Narcissa Malfoy is often referred to as Cissy by her family and close friends. This nickname is a shortened version of her given name and is used as a term of endearment. Additionally, some fans of the Harry Potter series may also refer to her as Cissy when discussing the character. **

Narcissa Malfoy is a complex character who is fiercely devoted to her family, particularly her son, Draco. While she is often portrayed as cold and aloof, her actions in the Harry Potter series show that she is willing to do whatever it takes to protect her loved ones. Her decision to lie to Voldemort about Harry Potter's death in order to ensure her son's safety demonstrates her loyalty and bravery. Overall, Narcissa Malfoy is a multifaceted character who adds depth to the story. **

Voldemort's arrogance and overconfidence in his own power may have blinded him to the possibility that Narcissa was lying. Additionally, Narcissa's fear of losing her son may have given her the ability to convincingly deceive Voldemort. Furthermore, Voldemort's focus on his own goals and desires may have made him less attentive to the subtle cues that would have indicated Narcissa's deception. **

Narcissa gets out of Malfoy Manor by taking advantage of the chaos and confusion during the Battle of Hogwarts. As the battle rages on, she sees an opportunity to slip away unnoticed with her son, Draco. She uses the distraction to quietly escape the manor and make her way to safety. Despite the danger and uncertainty, Narcissa's determination to protect her family ultimately leads to their escape from the dangerous situation at Malfoy Manor. **

Voldemort doesn't realize that Narcissa has lied because he is so consumed by his own arrogance and belief in his own power that he cannot fathom the idea of someone defying him. Additionally, Narcissa is able to maintain a composed and convincing facade, which makes it difficult for Voldemort to see through her deception. Furthermore, Voldemort's focus is on the bigger picture of defeating Harry Potter and achieving his ultimate goal of domination, so he may not see the importance of questioning Narcissa's loyalty in that moment. **