What is the role of a daughter towards her mother?

My mother took DIVORCE from my father in 2011 and left four of us in my father’s care. I am 16 years old and my sisters 14 years, 8 years and my brother 10 years old. From four years my father does everything for us (day to day care). He works full time and cooks food and does everything we also help him in home chores myself and my sister. My two siblings are very young and they don’t do it. At the time our mother was leaving us myself and my sister begged her not to break the family and she did not listen she said, “I am thinking about myself and you think about yourself.” And since 2011 she never looked back and never contacted us and never met with us and never enquired about our wellbeing.
Last year my brother was very sick all the information was sent to her and she did not responded back about his sickness she never called up to enquire about his sickness. What are the duties of a mother after she took a divorce and what are my duties towards her when she neglected, abandoned, rejected us and never care about us when we need her? She abused us by neglecting us? I do not have any respect for her? What does Shariah say about my duties and my mother’s role in these circumstances?