I am so terrible sorry and I can imagine your situation.
Supporting the abuser is common in the church. They judge on Sunday appearance alone and this happened to me too (although not in court). My wife would scream at me every single day for an hour. I grew up with an abusive father. I didn't know that this was that abnormal and marrying the first person I dated just added to the disaster of my childhood.
My wife would put on a smile on Sunday, impress everyone with her faithfulness and vast knowledge of the gospel (which she acquired since she spent all week studying it instead of taking care of the kids). As soon as we entered the car her happy smiles were gone and she would scream at me like a nutjob.
She ruined my manager career and members knew that we struggled. So whom do they blame? The husband whose task it is to earn the money. Not the poor stay-at-home wife who has such a hard life because of her evil husband and stopped working the day she married. This husband would endlessly critizise her in her stories.
The reality was that I would enter the living room and ask her to not forget to put the ham in the fridge (in example), since it was outside already for four hours while she was reading her books. Then she would flip out for an hour, block my way out of the room, scream at me until I reach my breaking point and tell her to shut up. Then she would cry and play victim and stay upset until I beg her for forgiveness. If I would mention that she screamed at me like crazy then all my efforts to calm the situation down were for nothing, because my apologies weren't sincere.
I actually blamed myself, because I heard this from everyone. I am not sensitive enough and even my mother told me that divorce would not help, because all women would act like this if they would be married to me. She accused me of just wanting sex with other women. It was a fucked up situation and it was all thanks to the church.
At church the leadership told me to not divorce as well while they kept blaming me for not doing enough (although I was taking care of children AND working).
Then I ended up in the hospital because of my wife and realized that they were all wrong. Doctors outside the church supported me and they were the first people in my life who told me that I need to divorce.
I do wish the best for your mother and your family. It seems that you do understand it but one thing you should know is that being married to an abusive person drives you in corners of yourself which you didn't know existed. People don't know what it feels like to be abused day in day out for many years, having no support, locking yourself in a room while the other person madly hits against it or running away while the abuser tries to hit and kick you. It is torture and can drive a normal person crazy.