Hahahahahaha, no way there's teachers able to protect students in magic school, ever.
Even including "western" magic school stories like hairy arse potter there's no such thing as a magic school that's safe.
Ok I thought of an exception, when it's a harem story and all the students are female, though to be fair those rescues are also last second saves.
That aside, she has magic that detects malice active, so why the hell can those kids run up and steal her compass with her not noticing them before they are standing behind her talking?