Mulder's eyes light up. "The New Age girl!"

Which is to say: He does remember her, given sufficient context clues. With those details - and with her hair a little fluffier than it was when they started the day - he can see the girl she was. He might be kicking himself for not figuring it out earlier, but at least he has it now.

"Did I end up getting you into hot water?" he asks, since it's not like he ever got the answer at the time. "With your family, I mean."