It was the first question she had thought of because it considered his origin. She wanted to know everything about him, and would in time. Especially if he was willing to be interviewed. It gave her hope that he might come back and allow her to dig deeper into him. For now, she was content with the basic questions. No use in scaring him away.
She listened to his calculated answer, finding the admission that he in fact was not from Earth to be thrilling. She definitely didn't mind the fact that he was an alien. It just made him more fascinating to her.
When he mentioned that he was the last of his kind, Lois frowned slightly. "I'm sorry to hear that. It must be hard." She replied. "Tell me more about Krypton. What was it like? If you feel like talking about it. If not then we can move on." She didn't want to stir any pain in him, especially since the was the last living thing from his planet.