Answer:
(Fatwa: 1090/911=D/1430)
A woman should be accompanied by a mahram in the whole journey of hajj, the husband of niece is not mahram to her; therefore it is unlawful to go to perform hajj with him though the niece is also with her.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
