I think this could be a loophole. Marga saying she's the werewolf being the truth, then following it up by a lie. I've blocked her twice and in those two nights, there's been no kills. I don't think a wolf would abstain for that long.
I don't think it's Brodie as, despite not being that active, has still been on the board during the day and night phases. As for Professor Speed, I doubt they would vote against a fellow Werewolf if they weren't going to be active much either.
I'm still voting to lynch Ai Edogawa.