I appreciate the help. I'm trying to slowly bring her over to being comfortable with it but it's already proving to be a very tough road. She's totally comfortable around me but can't get over the embarrassment factor of a public bath.
It would certainly make my trip planning a lot easier to get her over her fear. I don't know whether having non-Japanese people there would help or hinder. It's really tough to say. It's confusing for me because I wasn't brought up to be ashamed of nudity and didn't realize that this would be a problem until I brought it up during some trip planning discussion.