Yup, a certifiable nut. Though I must admit, the ability to sense magnetic fields with one's body is an intriguing idea... I just don't see how its terribly practical.
The more interesting thing to me is how the brain will learn to interprete the inputs.
If she can actually develope a tactile "magnetic sense" it would further enforce the hypothesis that the brain are incredibly flexible and capable of building routines, to the extent of adding another "sense". A good example of this is blind people "seeing" with their tongue (an electrode matrix set on top of the tongue, which due to its high nerve density offers fairly good resolution) developing an useable "sight" within surprisingly short time.
I suspect she would first either experience the stimulus as pressure, pain, heat or cold, but depending on how things work out, it is entirely possible that the brain could, with time, isolate these sensations under their own label.
Then it's just a matter of choosing what kind of sensory implants one would have, and to train the brain to identify the signals. Electric fields, magnetic fields, electromagnetic wave motion, cosmic ray detector...
And things need not stop here. If receiver implants can be used to enhance one's senses, why not make transmitter implants as well? Low-resolution ultrasound echolocation wouldn't be too hard to implement. Small ultrasound transmitter and receiver, a microprocessor driven doppler analyzer with output to a sub-dermal electrode matrix, on which the "image" is shown. Note that the transmitter and receiver need not be installed to the body though that would be ideal for portable version. The echolocation device could just as well be a high-powered doppler radar, or infra-red camera, or any camera for that matter. This type of technology could be used in vehicles like cars or airplanes to offer additional sensory inputs about the vehicle itself or its surroundings.
Even at low resolution, an "internal artifical horizon" could be fairly useful for pilots flying in IFR conditions. Similarly if they could have direct sensory access to the ILS system's localizer signal, it could reduce reaction times and make approaches easier.
Not to mention things like direct neural output plugs which could potentially make stuff like pointer devices ultimately useless and thus improve the human-machine interface and general ergonomics of things.
Also, obligatory xkcd plug
