Do we know the truth? The court will try to establish what is what. Why would a witness lie in court? They could easily get caught and render their testimony useless.
MG wasn't the one plotting to murder her husband and children. Being a religious fanatic (or a gullible follower) isn't a crime. Without the murders we wouldn't have heard of Chad and Lori. They would have been all still debating the end of the world in conferences and podcasts.
Of course none of us knows the truth about their relationship or lack thereof. It's possible that there was mutual dislike. Or maybe just disinterest. Perhaps MG just doesn't engage with her friends' children. Unlike Lori who was like a second mother to one of Tylee's friends. It doesn't mean much.
There's no proof that she did, although it's possible. I think she said in an interview that she never fully believed. At the same time she was ashamed of her gullibility. The zombie theory had no consequence for MG if she wasn't trying to murder anyone based on it.
Did Tylee believe in zombies? Or did she think that Chad and Lori were false prophets / scam artists and MG their groupie?
You mean her husband... Being a conspiracy nut isn't a crime. Murdering people is. MG and DW were among the chosen 144k. Why in the world would they get involved in murders that only benefited Chad and Lori? Lori repeatedly lied to MG (and everybody else) about JJ's whereabouts. She never told her that he was dead. Once MG and DW realized what was going on, they jumped ship (and so did Chad's friend CP, although much later). All IMO.