Margaret Peregrine is a high school sophomore. Most of the time, she's either at school, at the school robotics club, at the school chess club, or doing schoolwork. Today, she's cleaning out her late great-grandmother's attic.
Over the next few weeks, Bella and Margaret interview more students. A few of them sign on; others decline for various reasons (scared of runecasting, schedule incompatibility, wary of getting drawn into critter politics), but soon they have what feels like a reasonable class size.
They have dates that turn into curriculum planning meetings and curriculum planning meetings that turn into dates. They fix up the house and get it furnished with everything they expect to need.
Margaret makes a bunch of fruit flies unaging; by the end of the summer she'll know if it worked. She starts selling power strips that don't need a wall outlet and cell phone battery packs that look perfectly ordinary but last forever.
And then they start classes, because magic is awesome and everyone should get to enjoy it.