Hermes Gray is from a long-standing dynasty, which sometimes throws great heroes and sometimes throws ""great heroes"" who look very bad when history looks back at them.

He is determined, of course, to be the former. 

Unfortunately, an affinity for cats, of all things, is going to do him less than no good. He thought about bringing in kittens, but he'd been told in no uncertain terms that this was stupid, the caloric load alone wouldn't be worth the potential that they'd maybe catch a mal or two under the bed and it'd make him an instant target for any maleficer in the school besides. So that was for later, after graduation, and in the meantime he was going to have to just be a good enough poet the old-fashioned way.  

He is very good at that, at least. He waves a confident goodbye to his little brother, who he will totally see again in three years, it'll be fine. 

Lelina's parents are enclavers but her grandparents weren't. This meant she got told the comforting lie "you're one of them!" a great deal as a child. 

She's not not one of them, exactly - she gets the training, and the power sharer, and isn't going to have to do her own maintenance shifts, and all that. But Hermes is bringing in a tongue piercing that has imbued fifteen generations of his family with perfect pitch, and Madge has a knife that killed dozens of Nazis, and Lelina has - well, she shouldn't complain about a very nice brand-new shield amulet, but still. It doesn't feel like the same thing. 

She does like Madge, who's very sensible, but Hermes is exhausting. (Her mother has told her, glancing fondly at her father, that she might find him more interesting when she gets a little older, which is why she has a birth control implant even though that seems really unlikely to her.) They're both well-trained and going to be talented incanters, though, which puts her in a great position to be useful as the team alchemist. Her affinity is for potions, specifically - the further you get from 'a liquid in a bottle you intend to drink and get something positive out of it' the less it's her friend - but she expects to be able to handle the discipline in general. 

Margarete "Madge" Wagner is from a family of spies and cryptographers. This is cool and everything, she's very proud of being one of the very few native Germans who doesn't need to be any amount embarrassed by the work of her ancestors, but her affinity is a very specific kind of sabotage that will never be useful in the Scholomance, because it won't work on maleficers very well or at all and there's no one else it's likely to be a good idea to kill. And while she has put a lot of effort into her studies of politics, because she's going in with a head-in-the-clouds creative writer and an alchemist who has managed to skirt under the remarkable low bar of even less tactfulness than her and someone has to have any idea what's going on in the other enclaves, that's not really her area of competence either. 

(She thinks her area of competence is languages. This is not exactly false but at some point she's going to discover that her preferred method of solving problems is to punch them in the face, as non metaphorically as humanly possible.)