The magic of baking
Yes, Mona is a wizard, but her specialty is bread. Which is wonderful for keeping muffins from burning or convincing biscuits that they are not overworked, but significantly less so for defending the her city from an internal coupe and foreign invaders. Mona is a reluctant hero, who very rightly points out that she wouldn't have needed to BE a hero if the people in charge had just done what they were supposed to.