Ruling on the daughters of a son being uncovered before their grandfather’s wife’s husband

The question: Also, the listener Abdullah ibn Husayn al-Husayn from Hawtat Banu Tamim says: A woman has daughters from her son. When her husband—meaning the one who is the grandfather of the daughters—died, she married another man. Is it permissible for her son’s daughters to be uncovered before her last husband?
The answer: Yes, because he is the husband of their grandmother. The husband of the grandmother and the husband of the mother are mahram (a relative one may not marry) to the son’s daughters and the daughter’s daughters. They are mahram to them by virtue of breastfeeding, and also because here they are children by blood, not by breastfeeding. She is their father’s mother by blood, and if they were by breastfeeding, it would be the same.
So the result is that he is a mahram to them. The husband of the grandmother is a mahram to her children and her daughters’ children, and her son’s children from all aspects, whether they are children by blood or children by breastfeeding. Yes.