Tangles, chill dude
Kell's just trying to say that the cops have taken her details. If anything illegal happens and its reported, Kell is the one who will cop the trouble ... so in the eyes of the law Kell is responsible anything arising from the cruise. Which means in a very strong way, she does own the "responsibility" of the cruise. Kell, just like anyone else, is covering her arse by ensuring the cops have no reason to contact her for any illegal activity ... but ensuring the trouble makers are not invited.
It also makes it easier for those attending, knowing the cops will be laid back if its organised with a good crowd, and good reputation from the organiser.