Best case is it just blew a fuse in the radio....next best it blew up the radio.... worse, it blew up the amp... maybe a fuse in the amp?

Have her look at ALL the fuses under the hood on the drivers side and in the dash on the drivers side (open door and remove panel - easy access) also.... she could have blown one or more fuses that dont show up right away... or test every function in the car and see if it is working right....