Two suggestions:
A vigilante attempting to exact revenge on Chuck Bass for one of his many misdeeds (conduct as CEO of Bass industries, or maybe she’s the sister/family of one of his victims from his date-r*ping days). Think a more badass version of Juliet Sharp. OH MAYBE SHE KILLS HIM??? This is getting juicy lol
It’s weird coz she’s so much younger than the main cast is now. But assuming we’re talking about her being her current age in the original show, it would be cool if she was Dan (as Gossip Girl)s chief minion! She’s the person running Gossip a Girl when Dan isn’t... making posts that align with their interests, especially at times when Dan physically couldn’t or wouldn’t make posts (since we all know there are so many u defendable discrepancies.)