I still think that you guys are being way too passive in light of the likely demonic incursion. I mean one of the Grey Knights just got mind judoed by the old woman. It should be obvious that she's a fairly powerful psyker, who is hostile. And there are standard procedures for that. Even if you don't kill her directly she should at least be rendered unconscious or a non threat through some kind of nullifier. Every moment that a psyker is conscious is another moment in which they can summon daemons, open warp rifts, or just mess with people's heads.