...Well, since she's stuffing a charge onto her targets, wouldn't insulating boots be a GOOD thing, because it makes it harder for that charge to "leak" away? It's conducting shoes that would mess with her ability. I could also ramble about how it may not quite work as expected on metal armor due to charge spreading on and flowing across the outer surface of conductors, but....meh, physics.
That said, yeah, trying to dick with her stuff with real physics is a shitty thing to do. I will give a friendly reminder that purified water is actually a terrible conductor, simply because most people don't realize this. Most natural water's got something dissolved in it, though, so it's a non-issue in this setting, I suspect (and also WHY most people don't realize that water isn't always a good conductor). Until a priest shows up who knows "Purify Food and Drink."