What is incumbent upon the brothers of a woman who has been irrevocably divorced with a major, irreversible divorce, and who has five children, regarding her and regarding her ex-husband who is negligent in providing for their expenses? And does she have an 'iddah?

If a man divorces his wife with the third divorce, she becomes irrevocably separated from him (Baynunah Kubra). She is not lawful for him again unless she marries another man willingly, and he consummates the marriage with her, and then he divorces her or dies, and her waiting period (iddah) expires. She must observe the waiting period from the time of her divorce, and she must not spend the night anywhere but in her home. It is not permissible for her to reside with her ex-husband in a single house with shared facilities unless she has an independent dwelling with its own facilities and she feels secure. If the house is spacious and it is possible for her to reside in a separate place, such as a private room with a lockable door, then that is permissible. The preponderant opinion is that a irrevocably divorced woman (mutallaqah ba'in) is not entitled to maintenance (nafaqah) or housing from her ex-husband, unless she is pregnant. If she has no money or income, her maintenance is obligatory upon her affluent relatives. The custody of young children belongs to their mother, as long as there is no impediment on her part, and the children's maintenance is incumbent upon their father. If he fails to provide for them, the matter can be brought before the Sharia judge to compel him to provide maintenance.