Who is responsible for the financial and healthcare provision for parents in their old age and severe illness, given that they have a married son who is a doctor and a married daughter whose husband is at odds with her family, and is the daughter considered negligent for not moving in with them despite her regular visits?

The responsibility for the care and financial support of parents, when needed, falls upon all children, male and female. This responsibility is distributed among them according to their financial capacity, as Allah Almighty says: "Let a man of wealth spend from his wealth." If the daughter residing with them is sufficient for their care, there is no sin upon the other children for living far away, provided they maintain ties with their parents, treat them with kindness, and provide for their needs. If the parents require the presence of their children due to the daughter's inability or illness, then the children must move to them or move them to their homes. Any negligence on their part is considered a sin. The extent of care required from a married sister with children may differ from that of unmarried siblings.