Well dang, I really hope Patrick's soot power can help in this situation. The way her soot entered his mouth and eyes on the second to last page looked massively uncomfortable, and the "strings" coming from Margaret's face are just... I love horror manga, and those two pages are some of the creepiest I've seen. Thank goodness Shadows are basically just silhouettes, seeing that with a detailed face would be even more disturbing.
I'm still not completely convinced that Margaret will survive this though. I think Patrick might be able to neutralize her power but she'll still self-destruct, just on a smaller scale. Now that it's been revealed as a possibility, I expect to see some Shadow self-destruct at some point. And even if she DOES survive, I don't know how the adults will handle the situation. Will they have her eliminated for being so unstable and destructive? Or, if Maggie's alive, will they invite her since her powers are so strong? Or will they try to use her as a "back-up" for Barbara?
I just can't see a super-happy ending for Margaret with all the conspiracies in the house.