What should a daughter do with a mother who verbally abuses her, her father, and her sister with extremely vile language, knowing that the father might divorce the mother if he hears her cursing him again?

The daughter must honor her mother and treat her well, no matter how badly the mother behaves, due to the immense nature of her right. As it is stated in the Hadith (definition): "Stay by her feet, for there is Paradise." If advice would worsen the mother's behavior, then let someone she accepts advice from undertake advising her, while clarifying the impermissibility of cursing and the immense right of the husband, and what might result from that, such as divorce and the loss of children. She should also supplicate for her mother's righteousness, good character, and purity of tongue.