I guess we're still not sure of her current age? But if she was 13 at the time, and 'involved' (gag) with David, she could have been jealous. At that age of course they know right from wrong, but they're also not capable yet of *really* seeing the consequences, especially over the long term. It wouldn't surprise me if at the same time BB was in favor of any solution to get 'the competition' out of her way, as well as her brain not being able to grasp that David planning to murder Nicole would mean Nicole would be actually dead, for good. Yes, she knows dead is dead, but I'm not sure at that age she'd be able to grasp the severeness of someone planning a murder as it would also be very far out of her scope of reality. I'm not finding the words I'm looking for but I hope I've been able to somewhat convey what I mean. I'm not ready to crucify BB... there are numerous examples of grown adults who knew someone was planning murder and froze/had no idea what to do/had no idea they were serious/etc.. Or, BB could be a heartless so-an-so, of course. But, I can see where it could be she's not, and the whole situation was so ridiculously out of (her) reality that it didn't even sink in.