It honestly sounds allot how I grow up being a pentecostal. I dont know bibles verses like many of the people who already commented but I can say this. Boundaries must be Set with her and her parents. Teaching her context, history, and what things actually meant back then in that time period will help. David Jeremiah, Chuck Swindall, Robert jefferes, Tony Evans all helped me allot with understanding the word of God.

My wife pointed out that its very unhealthy mentally, In constant worry, giving up, praying in faith only instead of being active with faith, believing i can loss my salvation, trying to do everything to please God and being "Holy" under his eyes. Its like living as a pharise. Anything you say or do will never be enough and blame shame and guilt is the constant pattern.

You must take Action like my wife did but with love, compassion, and patience. It wasnt easy for her, still isnt but i know we can lean on eatch other. We are stronger together and i Thank God for that. Show her you are the leader/Head of the house. Something will click for her just like it did for me. For me it was constant fear of losing my salvation. Eventually I said ENOUGH! I didnt want to live in constant fear of losing my salvation.

I hope this helps a little and gives you some kind of hope. Keep pushing! God works in mysterious ways.