Is the person who brings up a foundling considered a Mahram to her?
A foundling should not be given the name of the person who raises them, and that person is not to be regarded as a Mahram to the foundling, (Part No. 17; Page No. 395) unless the latter is breast-fed by the person's wife or by a woman who is unmarriageable to him, whether because of lineage or because of a permissible reason, such as being his mother, sister, stepmother, and the like. Also, the child has to receive five breastfeeding or more within the first two years of their life. Undoubtedly, Allah (Glorified and Exalted be He) has promised great rewards for those who take care of a foundling and show kindness to them when their intentions are pure. However, a foundling is not regarded as a Marhram to the one who takes care of them, except under the above-mentioned conditions. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.