She's autism coded. Those brief periods of significant interest in learning a whole bunch of information on something relatively niche is exactly that. The interest doesn't last long, but you end up at least being familiar with it going forward. If someone mentions it, you can jump in and keep up with (and possibly even contribute to) the conversation.
Note: I have no idea whether she's autism coded on purpose or not, but regardless, she presents that way to someone familiar with the condition. She has at least two traits: the brief interests mentioned above, and the organizational efficiency/proficiency and focus she displays in her job.