The ruling on a woman uncovering herself before her sister’s husband if she was breastfed by that sister?

Question:
An older sister breastfed her younger sister. When the younger sister got married, is the older sister permitted to uncover herself before her younger sister’s husband?

Answer:
She is like a non-mahram, exactly the same. If she breastfed her with a legally valid breastfeeding of five times or more within two years, she became her sister and her mother. So when she married, her younger sister’s husband became the husband of her daughter. She may uncover herself before him, and he is forbidden to her because he is the husband of her daughter through breastfeeding. Yes.