This is a simplified analysis of Mary's reads, and I've had a little bit to drink so might not make a lot of sense, but..
Looking through Mary's post history, she did align her views with Chick's early on in post number #254, and her strongest scum read seemed to be Bianca. She also mentioned she was not quite sure where to place Evan, and that he might be scum buddies with Bianca. In post #501 she also brings up that she's mistrusting Glow, and possibly Kirby and/or Heyden.
Mafia choose to kill her over all the other possible targets. This was either because they figured she might have a blue role (would explain why she tried to keep a low profile), or because they wanted to throw off our scent by making a statement saying that we should look closer at her suspects. Essentially, it could be intended to frame the wrong people as scummy. That leads me to believe that maybe most of her suspects was wrong - Else it'd be almost too obvious to kill her for it. Plus I shared similar suspicions (especially regarding Heyden, but also Glow and Kirby to some extent), as did Dolby and a bunch of other players. Yet they choose Mary over everyone else.
But maybe her agreement with Chick regarding Bianca as scum is something we need to investigate further. It was a pretty early post, but now that Mary has flipped town and they had similar views, it makes Chick look better by default for having similar views as a confirmed Town role, and Bianca worse by default for being on the opposite end of the spectrum. I think this could be a set-up. That Bianca might be innocent, and Chick might be scum. It's subtle, and a little far-fetched perhaps, but worth taking into consideration.
Looking through Mary's post history, she did align her views with Chick's early on in post number #254, and her strongest scum read seemed to be Bianca. She also mentioned she was not quite sure where to place Evan, and that he might be scum buddies with Bianca. In post #501 she also brings up that she's mistrusting Glow, and possibly Kirby and/or Heyden.
Mafia choose to kill her over all the other possible targets. This was either because they figured she might have a blue role (would explain why she tried to keep a low profile), or because they wanted to throw off our scent by making a statement saying that we should look closer at her suspects. Essentially, it could be intended to frame the wrong people as scummy. That leads me to believe that maybe most of her suspects was wrong - Else it'd be almost too obvious to kill her for it. Plus I shared similar suspicions (especially regarding Heyden, but also Glow and Kirby to some extent), as did Dolby and a bunch of other players. Yet they choose Mary over everyone else.
But maybe her agreement with Chick regarding Bianca as scum is something we need to investigate further. It was a pretty early post, but now that Mary has flipped town and they had similar views, it makes Chick look better by default for having similar views as a confirmed Town role, and Bianca worse by default for being on the opposite end of the spectrum. I think this could be a set-up. That Bianca might be innocent, and Chick might be scum. It's subtle, and a little far-fetched perhaps, but worth taking into consideration.