Question: I am divorced and my child borne out earlier wedlock is in my custody. If I remarry will lose custody do the child?

Answer:

If the mother marries a person who is not a mahram [marriageable kin] relative of the child, i.e. this relative is such that nikâh under the right circumstances with him is not harâm forever, then the mother forfeits the right of custody over the child. However, if the woman marries a mahram relative of this child, and this relative is such that nikâh with him is not valid (for the child), e.g. she marries the child’s paternal uncle or any other similar relative, then the mother’s right of custody remains. In the absence of the mother, if any other woman such as the child’s sister, maternal aunt, etc. marries a ghayr mahram man (i.e. to the child), the same rule will also apply. That is, the right of custody over the child no longer remains with this woman.