What is the ruling on a marriage contract concluded with the guardianship of the adoptive family of a foundling girl, and what is the ruling on her intermingling with the sons of this family?

It is not permissible to adopt a foundling (laqīṭ) or to attribute him/her to the family lineage due to the forbidden matters that result from it. The female foundling (laqīṭah) has the ruling of an orphan, and her guardian is the Muslim ruler (sulṭān) or his representative. The majority of scholars hold that the marriage of a female foundling is invalid if she is not given in marriage by the ruler or his representative, while Abu Hanifa is of the opinion that her marriage is valid if she marries herself or appoints someone to marry her off. The marriage is valid according to the Malikis if her guardian directly conducts her marriage contract with her consent. The husband has the option (to annul the marriage) if he did not consent to her being a foundling and had not yet consummated the marriage after knowing of this defect, especially if the family had deceived him. The female foundling is considered a stranger to the children of her adopter and his male relatives, and it is not permissible for them to mix with her unless there is a proven mahramiyyah (unmarriageable kinship) through suckling between them.