Como Narcisa sabia que Harry estava vivo para perguntar a ele sobre Draco?

Ela verificou o corpo dele e sentiu as batidas do seu coração

Hands, softer than he had been expecting, touched Harry's face, pulled back an eyelid, crept beneath his shirt, down to his chest, and felt his heart. He could hear the woman’s fast breathing, her long hair tickled his face. He knew that she could feel the steady pounding of life against his ribs.

"Is Draco alive? Is he in the castle?"

The whisper was barely audible; her lips were an inch from his ear, her head bent so low that her long hair shielded his face from the onlookers.

^{Harry Potter and the Deathly Hallows Chapter 36: "The Flaw in the Plan"}

Narcisa recebeu a ordem de verificar a morte de Harry por Voldemort, que estava compreensivelmente paranoico de que algo deu errado, mas não tão paranóico que ele precisava ver por si mesmo.

Relacionando-se especificamente ao filme, parece que ela percebeu que ele ainda estava se movendo. Ela então finge sentir seu pulso para que ela tenha uma desculpa para permanecer acima dele, para ouvir melhor sua resposta à sua pergunta.

NARCISSA: Is he alive...?

EXT. FORBIDDEN FOREST - CLEARING - NIGHT. Harry lies face down, glasses askew. He OPENS his eyes a millimeter, finds Narcissa’s face swimming in the dawn’s muted light, eyeing him with a strange intensity: the question, he realizes, was posed to him.

BELLATRIX: My lord, let me help you -

VOLDEMORT: I do not require assistance.

Across the clearing, Voldemort rises shakily, Bellatrix at his elbow. The Death Eaters watch, stirring uncertainly. Voldemort glances toward Narcissa, toward Harry. Bellatrix detects the wary glint in his eyes.

BELLATRIX: The boy. Is he dead?

Harry’s eyes shift, meet Narcissa’s once again. Something in her expression... He closes his eyes. She places her fingers over his heart,

NARCISSA [WHISPERS] Is he alive? Draco?

Harry hesitates and then... nods -- so subtly it’s barely perceptible. Narcissa withdraws her hand, turns to where Bellatrix stands alongside Voldemort. Nods.

The Death Eaters CHEER. Hagrid HOWLS in misery. The news seems to rejuvenate Voldemort. A fierce glint returns to his eyes. His stature grows. He eyes the Elder Wand... and smiles.

_{^{Harry Potter and the Deathly Hallows, Part II - Original Screenplay}}