Rebecca was hard to convince should she decide it's not worth the risk at her side. But Leila is very convincing when she wants to be. After a few exchanges of words the two haad come to a consensus of the teacher being their protector of sorts.
With the concerns she has in the high risk members of their group it is the most reasonable compromise the teacher could make. The principal would approve of her approach as they cannot just leave their students with problems. Not because it is their responsibility, but rather because they are concerned about their well being. There are plenty of examples of what happens with young mana users with such traits. And most of the time it does not end well.
