Electrons can’t lose their charge through radiation because they can’t have fractional charge. They radiate photons to lose momentum. (They can become uncharged by combining, eg e+P = N).
A black hole can presumably radiate charged Hawkings radiation? I.e. if an electron-positron pair is created near the event horizon of a negatively-charged black hole then it would disproportionately capture positrons and repel electrons, thus radiating away its charge. (Could be wrong here, I’ve not looked into charged black holes before). I would assume here that charge radiates away at a different rate than mass, and by her statements it sounds like ch argue evaporates away quicker.
She’s not making a general claim that “everything that radiates loses charge”, that would be silly.