What is the religious ruling on visiting the mother without staying overnight with her due to circumstances of childbirth, the infant, and so on? And is the mother's care incumbent upon the daughter or the son who mistreats her?

The mother's right is great, and honoring her is among the most obligatory duties, especially in her weakness and illness. Serving and caring for the mother is obligatory upon all her children, either by residing with her, or taking her into one's home, or providing someone to serve her, or by taking turns serving her. If you are unable to care for her, you are excused, and your siblings must undertake this. It is not permissible to leave the mother alone in a way that harms her. The brother must be advised and warned about the severity of disobeying parents, and the mother should gently be advised to be fair among her children.