I may as well explain some of the slang happening here.
To “know one’s knowing” is to be an expert, as you can guess.
Meanwhile, for Sonia and her new friends to “put a hat on” something would be to throw a wrench in it. I haven’t been able to find much about the origin of this curious faerie idiom. There doesn’t seem to actually be a stigma against hats or uniforms, although it may come from the general sense that the act of putting a hat on someone else implies that they do not have control over their appearance. This is the best guess I have based on the observations that even Jeenare soldiers are known to dress as individuals rather than in exactly common uniforms.
(This is definitely not to say that they are immune to the magnetic draw of fashion trends, particularly in common circles.)