Is a woman’s’ sisters’s son-in-law a Mahram? 

Q. Can a woman travel with her sister’s son-in-law as her Mahram for Umrah or Hajj?

A. It is not permissible for a woman to travel with her sister’s son-in-law as a Mahram for Umrah or Hajj as he is a non-Mahram (stranger) to her.

Allah Ta’ala Knows Best

Mufti Ismaeel Bassa

themufti.com