Okay Gav... you start throwing in Math jokes, it is time for this Math major to chime in...

Her level is only negative, not imaginary. For her level to become imaginary, someone has to root it. If you exponentionalize it, with an even number mind you, then it would become positive...

Of course you can express roots as an exponential, but usually as a fraction... Then the denominator of said fraction, must be even.