Just throwing my hat into the ring so you can laugh at how ludicrously wrong I am.
Seb: Rebellious and eccentric. Extra for the sake of being extra, but fiercely loyal to her family and friends.
Katarina: Smart and elegant, a little bit bitter, acts older than her age.
Josie: Short, sweet, slightly adorable but can still kick your ass (aka seems like a cinnamon roll but can actually kill you), hates anyone who dares to call her 'Rosie Josie'
Adeline: Not immediately likeable but grows on you overtime. A little prissy, but does what needs to be done. Falls in love easily.
Eiffel: Tall. Talkative (like seriously won't shut up.) He infuriates his siblings but they still love him. (deep deep down)
Ray: Total bro, needs someone more reserved in his life to keep him grounded and stop him from doing impulsive stuff that could get him killed.
Arthur: bold, a tendency to be a little rude (this one is maybe not accurate, I associate Arthur with king arthur y'know? It overpowers my judgement)
Edmund: an intellectual, probably is close friends with Katarina. His friends have tto push him to be brave.
Oh and I know this isn't at all related to what you asked but I'm going to guess who's a couple (in the event that they are all even of dating age, are dating, and aren't all cousins and aren't gay.) Eiffel & Josie, Arthur & Katarina, Adeline & Ray, Seb & Edmund.