User blog comment:Braydenrules/Batgirl rules!/@comment-5553705-20121029225620/@comment-34954086-20121030102155

Designations B16, all alter places are filled by people some of which we know are newer (Cass, Robin III, Beetleboy etc). On the team there's only room for Jason before her. Though that isn't a guarantee. Red Arrow is before Zatanna in designations afterall, Jason couldve simply been given a designation in good spirit, while she did not (which by the standard Batgirl-Batman initial relationship, makes sense) and she was allowed to join later when properly welcomed into Batfamily.