Nicholas teaches her how to fire a gun. Reynard, how to do so stylishly and with feminine grace.
Crack, shaking his head, teaches her how to disabuse a man of the notion she might make him a helpless victim without a need for either guns or graces.
"Won't kill him," he tells her, with a sideways look at Nicholas, who shrugs. "Only makes him wish it would," which is Reynard's cue to grin conspirationally at her, as if to say: us against them now, sister.
(And so it is, more often than not.)