That is really interesting about your daughter's static accumulation! There is actually such a thing as a static electricity detector to measure her accumulation. I see some for sale doing a Google. They can be made fairly easily too with a jfet or mosfet transistor and a LED:
Static electricity sensor : DISCRETE SEMICONDUCTOR CIRCUITS
The ground wire on the PC should connect to the case inside the PC's power supply and hence ground the case. But if the electrostatic field was high enough, and close enough to the front of the PC, it may be possible to get a static accumulation through the plastic parts on something like the reset button. But even then I would expect those circuits to be low impedance enough to prevent that from happening.
If I were troubleshooting something like this, and had verified that the wall plug ground was good and the panel ground was good, I would probably remove the PC's power supply next and either dismember it to check the ground connection inside, or simply swap out the supply with another.
If I were testing that wall plug ground I would also use something like a 100watt lightbulb in a lamp that would pull 0.8 amp. Then measure the voltage at the plug with the lamp plugged in (hot to neutral). Then I would run the lamp from hot to ground and do the same voltage test and see how the two compare. Often grounds are daisy chained through the various wall outlets and junction boxes on their way back to the panel. Even with a dedicated circuit it may go through a couple of junction boxes back to the panel. If any of those connections are loose or corroded you will get a bad ground.
Another fun thing that happens, especially with older electrical breaker panels, is the screws loosening up. Something to have your electrician do is to re-tighten all the breaker screws, neutral screws on the bussbar and all the ground screws on that buss bar. And while he/she is in there have them pull the feed breaker or fuse and check the tightness of the setscrews on the large wires feeding the panel. I've seen a nice large arc/spark come out of the feed setscrew on a 100 amp panel that was running at 98 amps (being replaced and upgraded) when that feed wire was moved slightly (loose screw!). Interesting enough that situation had large amounts of noise on the electrical plugs - they had surge supressors everywhere - which all then went away.
That loose connection was just sitting there sizzling and creating noise throughout the building.
One other random thought. Try replacing the A/C power cable going from the wall outlet to your PC. The crimps on the ground wire at either end can go bad just like the crimps on the hot and neutral wires can do. But its never noticed since the PC keeps running just fine, at least until something like this comes up.
