That I am going to perform Umrah with my wife and my sister in law who is married, but her husband is not in capacity to perform umrah with her, and no any brother want to go with her, so she willing to perform umrah with us. Can she go for umrah with me and my wife?
بسم الله الرحمن الرحيم
(Fatwa: 1207/1274/L=11/1438)
It is necessary that the woman accompanies some mahram during hajj or umrah. Bahnoi, according to Shariah, is not a mahram. Thus it is not lawful for your Sali to go for umrah with you and your wife.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband