Is it permissible for the husband to legally register his wife's daughter—who recently embraced Islam and has a daughter from a previous relationship with a Muslim man who abandoned his daughter—under his name, due to the impossibility of proving her biological father's name? And does the ruling differ if this daughter was a result of a legitimate marriage contract or a casual relationship before Islam? What is the legitimate relationship of the daughter with the rest of the husband's children and household?

A child born out of wedlock is attributed to its mother, not to the fornicator. If conceived through a legitimate marriage contract, the child is attributed to its father. Adoption is forbidden in Islam, based on the Almighty’s saying: "nor has He made your adopted sons your [real] sons." It is not permissible to attribute the daughter to the husband. The daughter is unlawful for the husband if he has consummated the marriage with her mother. She is permitted to unveil in front of him, whereas his children from other women and his relatives are considered strangers to her. The girl can become unlawful for his brothers through suckling if she breastfeeds from their sister or wife within the first two years of life.