When does a step-daughter become a Mahram? 

Q. My brother is married to someone who has 2 kids from her previous marriage. One of the kids is a girl. We would like to know If my brother is a mahram to his wife’s daughter? Please elaborate further.

A. If a husband consummates his Nikah with his wife, he becomes a Mahram (non-stranger) to his stepdaughter. (Nisaa 4/23) The ruling is the same even if the wife passes away or the marriage is terminated.

Accordingly, your brother becomes a Mahram to his step-daughter once his marriage is consummated with his wife. (stepdaughter’s mother).

Allah Ta’ala Knows Best

Mufti Ismaeel Bassa