Nobody was able to tell Rebecca what to expect her lab assignment to be since apparently unlike shop those aren't standardized even in the first week. So she has to get her assignment before she goes to the cupboards, and somebody else, who finds his assignment right away and heads straight for the supplies, gets ambushed by a spider-snake-thing and barely manages to nail it in the thorax with the nearest Bunsen burner. That after it's bitten him in the nose. Somebody volunteers to brew him an antitoxin and he accepts what sounds to Rebecca like maybe a kind of extortionate price, all his snack tokens and a chunk of mana and the artifice he has pinned to his shirt whatever that is, but it's not like she can undercut it. Nobody's undercutting it at all, so maybe it's a perfectly fair price. Bitten kid does seem pretty faint.
...well, there's her assignment. She is going to brew a tea that will... prevent her from getting her period? Oh, that's really cool, actually. Periods, who needs them. Not wizards!
She spends kind of a lot of the lesson figuring out how to operate her Bunsen burner but once that's done she learns the two-line song she's supposed to sing while she boils the leaf in the water and then she's got a flask of an amber tea that looks like it's supposed to. She takes a sip since she is feeling kind of crampy now that she thinks about it, and, wow, that worked fast. Hunts for something to use as a flask stopper so she can take the rest to her room.