She can tell; but she isn't sure why he is relieved at all.

"You also like to feed your ego," she reminds him. "So I'm sure you think they're always relevant." It still gives her time to go over what he said, with keeping in mind the fact he's insisting it is a relevant question to ask. Instead the reason occurs to her.

"You think I came from a different time than you!" As much sense as that doesn't make, it still does at the same time, a bit at least, if only because his comment about Ghastly and the amount of time he won't be missing is fresh on her mind. "Why is that?"