Damn, Akira roasted that girl with no mercy. The characters don't feel too annoying yet as we are just introduced to them. The girl might change after this reality check.
Well she says that as a way to measure him up while also indirectly telling him to watch himself in case he might be a threat to the young lady she is responsible for. Kinda her job to act like that so I see this as reasonable for her, she even tries to teach the young girl on the side too so it's not complete blind obedience.