This story hasn't aged well.

The precocious child being so much better than her peers is fine and a decent dose of realism. Some kids are just smarter than others. The extreme abuse in a school setting isn't healthy or something we should be normalizing. We shouldn't be telling kids the only way they can get rid of an abusive teacher is by scaring them with a ghost. The idea that a child with special powers could help right a wrong is great. Matilida understanding Mss Honey has suffered and been stolen from is a good way to show kids that adults have problems too. I also liked the message that kids need to challenged based on their abilities and if that means skipping grades, they should skip grades.