adopted

Assalam-o-alaikum,Dear Sir/Madam,I would like to inquire about the status of an adopted child and any rules concerning domestic ethics and pardah. The case is a rather specific one. One of my aunts adopted a boy who is the mehram of her sister in law since he was breast-fed by the sister in law.Is my aunt a mehram of the adopted son? If not then what  rules should she observe regarding pardah and other relevant matters.

I have a stepson who is 10 years old. Do I need to convert him to Islam then make him adopt an Islamic name. How do I do the adoption procedure? How about his "bin," does he need to be "bin" as Abdullah or with my name.

As-Salamu `alaykum. I converted to Islam a year ago. I was married for many years and divorced before converting. During that marriage, my husband and I legally adopted a baby. By Canadian law, we have no information to identify the biological parents and the child was named by us. He is now 12 years old. He has known the story of his adoption since he was a toddler, and by law at 18 he can ask the government for information regarding his birth parents. Should I change his name now? What name should I use since we do not know his natural father’s name?