Second, the authors do not mention why they implicitly selected an additive model (i.e., each factor makes a unique and independent contribution) instead of, for example, an interactional model.
First, some factors (i.e., CU traits) may be predictors whereas others (i.e., delinquency) may be correlates or consequences of relational aggression. If the authors are really interested in the processes that could feed into reactive or proactive relational aggression in females, they should have been more attentive to this issue.