My wife just got a used Mid 2011 MacBook Air. The keyboard looks like this:
But the keys work like this:
There's no way no adjust the backlight brightness and the volume controls are all messed up. How can I fix this?
I am back after reinstalling my old flaky trackpad. My function keys are back to normal. This shows that the trackpad somehow interacts with the keyboard layout but I can not tell you how. Since the mid-2011 Air models seem to have numerous trackpad problems, it is possible your wife's used one had had the trackpad replaced.