I think Vesta is very similar to a lot of anime characters who are sweet and motherly, except for the fact that she is, surprise, not the pushover she seems. I hinted at this in a previous chapter (Ch. 8) but when she does eventually lose her temper, she LOSES IT. She's the slow-burn type when it's her own problem, but she has an explosive temper if the victim is someone she cares for. And now all the girls know that.