what to do to plan for divorce

asking for help for my friend's mom

her dad used to abused her when she was younger but her mom forgave him. Now when my friend is 20+ year old and told her mom that she should divorce him since he had not change, she agreed.

her mom has 0 income and is a housewife while he earns abt 3k. he can get quite physcial as well so they have to leave privately. since she has no income, she is afraid of the cost to get a lawyer. any advice for her mom? they recently bought a new house together 50/50