I suspected it came from something like that but it's nice to have verification I'm not as confident with translations with this one, particularly when she's talking about the teacher Special thanks to Kags for translation assistance
1 year late, but no, she's not talking about the handwriting. Pretty much what follows what you translated correctly (the polite part). If you use perfect Japanese combined with proper keigo (sonkeigo, kenjougo, teichougo) in speech, or letters to some Japanese friend you just knew, this is the kind of compliment you will normally receive. being teinei; kirei na nihongo. I've encountered that many times back when I was still actively studying Japanese in academic settings.