I’m rewatching the series and the first 5 episodes Sheryl was a great grandma and loyal to her family. And then on episode 6 with the prophet, who tells Kristin to avoid red for 7 days, is where Sheryl ends up having s-x with Leland and there’s fire around them symbolizing her having relations with a demon since David says he believes Leland to be a demon. Sheryl is wearing red lipstick in that episode and after having relations with Leland, she goes to his closet and grabs a red dress. I feel like she became evil or became possessed after sleeping with Leland?
Never mind just watched season 3 and I think she’s Evil because she had the chance to have Leland exorcised and instead she helped him recover.