Tutor Olana isn't quite as mean as Miss Trunchbull, but she's no Miss Honey either. The teacher charged with running the princess academy is the kind of no-nonsense woman who literally throws girls into rat-infested closets for speaking out of turn:
Gerti is in a closet thinking about speaking out of turn. These fine soldiers will be staying with us this winter. Should any of you have ideas about questioning my authority, they are here to make it clear. (3.141)
Tutor Olana's obviously got a thing against the mountain girls when she arrives, and she starts off by insulting them and saying that she thinks it will be a lot of work getting them to look and act presentable. Gee, thanks. But in the end, she reveals to Miri that she didn't actually dislike the girls; she just wanted them to do their best:
"Tell the other girls that I… you might explain how the burden of turning rough mountain girls into princesses, on my shoulders alone…" Her voice tightened, but if she was near tears, her eyes did not show it. (25.127)
Her teaching method isn't going to win her any friends, but in a way Tutor Olana succeeds in the end—all the girls end up learning their lessons.