I’m in a situation and it requires deep thought. My husband has a son from his ex wife, and his ex wife has another son from her first husband who is also her ex husband. So my husbands ex wife has two sons from two different men. I’m currently pregnant and quite possibly might be a girl. My husbands step son doesn’t live with us but he’ll probably consider living with us when he turns 18 he is currently 13. So in five years he’ll be an adult. My question is in order to make him halal on me, so I won’t have to wear hijab if he decides to live with us, can he marry my daughter because she will be his step sister? The only concern is that he has a half brother (my husbands son that currently lives with us) making it hard to decide if that’s halal for my husbands step son to marry his half brothers sister? Even though his half brothers sister is not biologically related to my husbands step son at all.
If your husband has a biological son, your daughter cannot marry him. But if he has a step-son (meaning he married a woman who had a son from another marriage) then your daughter can marry such a step-son.