Two babies suckling from the same woman in different times
some people are breast-fed by one woman or by the wives of one man five times for each during the first two years of their lives, they have become siblings by breastfeeding, regardless of whether the period between breast-feeding each of them is long or short. Accordingly, each one will be the uncle or aunt of the other's children. Furthermore, they become Mahrams (unmarriageable relatives) for one another. As such, they cannot marry each other. However, it is permissible for one of them to (Part No. 21; Page No. 125) marry the sister of his sibling by breastfeeding, provided that she has not been breast-fed with them from the same woman.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.