Welcome James! Lis here and I have five (for now).
Marguerite "Daisy" Rosier (this girl) - Slytherin a year below Hamish when he was in school. She's a bit standoffish, but that's mostly to cover up her deep-seated insecurities and her natural legitimacy abilities. She's a sinnamon roll mostly and keeps fairly mum on the protest issues as she agrees on them mostly, but her family being what it is, she doesn't want to disappoint them.
Percy Weasley (arulefollower) - He works in Operations for the Knights, aka he's a baby Coulson. He's fairly similar to canon, I think, though less full of himself, maybe. He's worried about werewolves in a scholastic/intellectual sense, but on a day to day basis he's just stuffy/formal/overly polite.
Justin Finch-Fletchly (justifiability) - Muggleborn and trained as a muggle solicitor, he now works for the magical court system in the eventual hope that he can have a positive effect on the magical world. Or you know, up end it. He was a year ahead of Hamish, also a Hufflepuff. He seems to be a mom friend in this incarnation.
Ric Bones (profane) - Amelia Bones' adopted son, the same year as the Weasley twins. He's a smart alec and tends to comment all over. He works as a freelance cursebreaker/security expert. Too smart for his own good. Has a dumb-looking dog called Archimedes. He couldn't give a shit about werewolves.
Regulus Black (excellency) - The Crowned Prince. More closely aligned with the previous king in terms of politics, but keeps pretty mum about that. He believes himself better than everyone, by virtue of being royalty, but he's also polite? Exceedingly careful, Reg thinks longterm but would like nothing more than to hang out with his wife and their daughter rather than run the country.