How often do you see oppositional defiant disorder in girls?

Can be fairly common. The frequency of oppositional defiant disorder can vary depending on the study, with some studies reporting rates of 2% and others up to 15%. It is generally noted that rates are higher in boys before puberty, but then become more equal in adolescence.
Evaluation needed. It is more common in boys, but is becoming more frequent among girls. Teen girls are more likely to be diagnosis with borderline tendencies. And evaluation and treatment are certainly needed in either case. The disorder is also often related to earlier unresolved trauma.