Your actions might save her! Keep praying. But be careful Madeline. One time, when my Mom was hitting me I cried out loud to God, "Please don't let me hurt my mother, God, please don't let me hurt my mother” I was seriously crying out to God for help, because I am much stronger than her. But that made her angrier and she only kicked me harder. And whenever I let go of her wrists I would be slugged again.
So, be careful. Our mothers need help, but talking about God won't do it. That will enrage them and force them to do anything they can do to shut you up. At times, you may have to do your bible reading while hiding; but remember God is there for you. He hears you when you cry and rocks you gently in His arms. Just remember stand up for what you believe in.
I find it much easier to pray in front of her when my dad's mom is around. That's when I can talk freely about God and I do. I push a little farther each time. So far I have been completely safe doing it this way. Maybe you should try something like that. Find someone who you can talk to God to (in front of your mom), where she has to control herself. It's just beautiful!!