When she told me her name, I didn't ask her to repeat it, and I got it right through the rest of the call. Whisper didn't, so how is this "at least s good as a human?"

I wouldn't expect any transcriber to know that the correct spelling in your case used a G rather than a J - the J is far more common in my experience. "Jim" would be an aberration that could be improved, but substitution "Jem" for "Gem" without any context to suggest the latter would be just fine IMO.