I would like to ask a question relating to financial support for the husband's family. For example, the husband is from a very large but poor family, he is living in a European country with his wife and two children (both man and wife work). Despite the large family in his home country the family ends to rely on his financial support on a regular basis. The man and woman put their earnings in "one pot", hence her money is also used to finance the needs of his family. To what extent is the son obligated to finance his families needs and to what extent does the wife have to help?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If this man has more than what is necessary for spending on his wife and children, it becomes obligatory on him to spend on his parents if they are poor. Allah Says (what means): {Worship Allah and associate nothing with Him, and to parents do good...} [Quran 4:36]

Spending on the parents is part of doing good to them. It is also obligatory on him to spend on his poor brothers and sisters who do not have a source of income.

Allah Says (what means): {And upon the [father's] heir is [a duty] like that [of the father].} [Quran 2:233]

The meaning is that the one who may inherit has to spend on any person from whom he could inherit if that person dies. This verse is evidence, according to the Muslim scholars, for the obligation to spend on close relatives.

Anyway, this man has to help his family as much as he can without neglecting spending on his wife and children.

But the wife is not required to spend on anybody nor to help in the home's expenditures or to give anything to her husband's family.

But it is desirable for her to help her husband accomplish the duties and obligations due on him. If she does so, Allah will reward her, Allah willing, for that if her intention is to please Allah, The Almighty.

For more benefit on the obligation on the husband to spend on his wife, please refer to Fataawa 396145, 384544, 168551, 85361, 116345, 91310, and 278863.

Allah knows best.