Haven't watched the latest season regularly, but that teacher was horrendous. I hated her voice. It grated on my nerves and her manners were atrocious. If she'd treated them with courtesy they probably would have thought she wasn't so bad.
Poor Edith. I swear Fellowes had an ex GF named Edith who brutally tore his heart. lol Mary's so rude but gets everything her way. /rant