Marrying the sister of a brother by breastfeeding

Q: My mother, may Allah protect her, breast-fed a child along with one of my elder sisters. Is it permissible for me to marry one of his sisters?

A: If the matter is as you have described, it is permissible for you to marry one of his sisters as this is not affected by your mother breastfeeding him.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.