Sounds like either a dodgey connection thats just finally fallen out or something just fried itself. Shaking the keyboard about wont have done anything
unless she pulled it really hard and the USB connection snapped on the motherboard and it caused a short-circuit, but that is pretty far fetched.
Firstly - turn it off and on again and double check all the connections.
Then the best thing you can do is take a look inside it really and check for anything obviously wrong (smoke, unplugged cables, insects) - this does of course require at least some knowledge of how things inside it should be. Really does help to know a thing or three about PCs before buying an expensive one
