Yep, you got it. Or you could ochestrate it in a way that suggests that every human being has a bit of latent magic in them, & that these 2 are just drawing these powers out in their less-than-supernatural friends. Hmm, maybe you could say that magic becomes more unsteady as you grow older, especially if you don't know how to control it. If you've seen the movie 'The Covenant', they "came into their powers" i.e. reached their magical peak, at the age of 18. Also, you could mention that if you don't learn in time, most witches go crazy as the pent-up magic has not been released properly &, therefore, has nothing to do except attack the host. And, if the host dies prematurely, the expulsion of magic could result in a cosmic blast, which in turn creates a vaccuum or black hole where the witch falls. You could also work around the idea that maybe the grandmother taught them the basics of control but that wasn't even close to helpful enough as their powers develop. Therefore, they instinctually channel it through other vessels aka their club, which is of course (in this particular scenario) illegal.
The characters are like twelve does that effect anything? And what might witch society be like? And any opinion on familars?
So how's this for an interesting plot set up? The cousin's grandma has just died, and the wider witch community couldn't intervene in time to keep them from being placed with normal foster parents.
