guardianship

Forbidden to you are your mothers and your daughters and your sisters and your paternal aunts and your maternal aunts and brothers' daughters and sisters' daughters and your mothers that have suckled you and your foster-sisters and mothers of your wives and your step-daughters who are in your guardianship, (born) of your wives to whom you have gone in, but if you have not gone in to them, there is no blame on you (in marrying them), and the wives of your sons who are of your own loins and that you should have two sisters together, except what has already passed; surely Allah is Forgiving, Merciful.