بسم الله الرحمن الرحيم
(Fatwa: 32/29/B=01/1436)
After marriage, the mother-in-law is like mother while father-in-law is like father. It is necessary to respect both of them. It is a part of good behaviour for daughter-in-law to serve them. However, it is not wajib or necessary as per the Shariah i.e. if the daughter-in-law did not serve her in-laws, she shall not be accountable before Allah. But if she serves then she shall earn reward.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
