I'm pretty sure that the only persons a military police can charge is a military person. It has to be the RCMP, or local police force that would charge her. Military police can arrest her for being on a military base, but would have to turn her over to local authorities.
As for uniforms, go down to the local army, navy store and buy whatever used uniforms you want. Old uniforms are sold off at auctions.
And people can make their own uniforms, as long as they are not like the Canadian Armed forces uniforms.
The big thing is people wearing medals that are not theirs to wear.