There's definitely a baffled stare from her as he says that. She really wants to react much more politely than that, and in an ideal situation she would. But Chizuru wears her heart on her sleeve, so there's no way she would be able to hide just how surprising that statement is to her.

"That.. seems like a really long time to live, if you don't mind me saying that. I can't even imagine it.."