Jesus H Tapdancing Christ that's a BRUTAL way to kill someone??? For fucks sake you prepped poison and now you're going to run with 'death by smoke inhalation and burn shock'? I mean I get the sense of it; it's hard to place timing of when a fire starts, and no evidence will be left behind (provided she dies). It's not like crime scene investigation exists yet. As far as 'ill thought out murder that it's possible for the ML to stop in progress Plan B' its brutal, but makes sense.
But. There's wanting someone gone, and then there's raw fuckin cold blooded shit. Lord and a fuckin half.
I kind of feel bad for the red haired woman. Like she sucks, but it's super, suuuper clear she's never been comfortable with killing someone. (At least not like, cold blooded, with her own two hands.)