She MIGHT get off with psychiatric institutionalization and probation / community service based on testimony and mitigating factors since I strongly suspect the only victims still around to testify against her are Maria and the MC. Of course this is all assuming some sort of non-corrupt law enforcement involvement and dependent on what actually happened to those older girls and her role in their fates.
Based on what we've seen so far though, I'm all for letting her rot somewhere, assuming she survives.
The big issue with her is she's the one fostering the girls and the one that owns the house. If she's removed from play (short of just "disappearing" her in the woods and not telling anyone) the whole situation falls apart. No money, foster family broken up, siblings possibly separated, etc. MC needs a way to "keep the party going" so to speak, which I guess is where the website comes into play.
Anyway whatever happens, we're going to get a chance to icepick uncle shithead in the eye at some point, right? That motherfucker touched Sam, and I swear I will flip this desk over if he touches Lucy.