Bullshit. I'm not assuming that. Hell, I'd probably take her up on the offer myself if I didn't think her sister would kill me.
But, from what she's said about not caring if she dies, yeah... I don't think she's capable of judging a situation properly. Personally, I don't want all hell to break loose again. I want to get through the next seven months without this island breaking out into a goddamn war. If someone goes and kills the Slayer's sister, there's gonna be a fucking shit storm.