The shocking part of this, is that her publisher can read HFS floppy diskettes. I suppose, at least she doesn't need to worry about the files in WordPerfect format, but I would think that they would have one terrible time of trying to determine why the media is 'unformatted', unless she sends them in DOS format.
I seemed to recall that it was going to be DOS format. And Word 5.1 writes perfectly-compliant .doc files, that even Word 2013 reads just fine. (This incident was many years ago now, before .docx was invented.) Although you do need to turn down Word's built-in security settings to allow it to open, since Word 5 doesn't have any macro-virus protection, so it assumes all old Word files are suspect.