The comic insinuated that she wasn't above screwing with the professors to get a higher grade on her reports, among one of the reasons why she got her degree in the first place.
I don't know who the fuck Talia is to Batman, but he ignores her in favor of mourning the Joker. I can't help but wonder what he was planning to do with that body before the police arrived.
Maybe he engineered something that she then smelled out of the flower? He engineered a way to turn Tim into a puppet of himself 40 years after the Joker had died.
They finally answered this in the almost-series finale of JLU, where Terry McGinnis and Bruce Wayne have a brief falling out. Joker was using the alien technology introduced in this episode:
http://www.poetv.com/video.php?vid=67759
I think it sat poorly with the "Batman Beyond" writers that a guy who makes laughing potions could also build mind control microcircuits, so they were eager to shoehorn in a better explanation when the opportunity appeared. Throwaway line a little bit after 8:28: