Is it permissible for me to marry the children of my father’s former wife?

Question:
My father married a woman, then divorced her, and he had no children from her. Then she married another man, and he had sons and daughters from her. What is the relationship of these children to me? Is it permissible for me to marry these daughters?

Answer:
Yes, yes, they are not your sisters, but they are stepdaughters to their father, even after the divorce. As for you, no, they are not your sisters. Rather, they are on your side, and they are closer to their father’s wife. Their father is not your father, so they are not mahram (forbidden relatives) to you. Rather, if he married the daughters of his father’s wife who are not from his father, provided there is no breastfeeding between you.