Definitely sounds like a super frustrating situation. I've known a few people that didn't like having their views challenged, very annoying especially when they are objectively wrong.

Using buzz-phrases and thought stopping techniques is unfortunately one of the signs of a high control group. It's a tactic used to keep people from questioning, and unfortunately it's often done by the people not by those in leadership. It's a sign of Thought Control, one of the four points on the BITE model. A model used to determine how controlling a group is. It's mostly used for cults, but applied really well for any group.

At least it sounds like you have a good way of thinking though, a desire to learn is important! And a desire for truth is even more important! Maybe one day you can find a way to let your mom think a little bit more about her beliefs. And if not, hopefully you can find a way to set up boundaries with her.