"I am your fourth sister": a stranger sent letters to three women, assuring them that she was their sister. So with which of them will the kinship be confirmed?

After the sudden death of the mother of a 15-year-old teenager should be taken to an orphanage, because officially he remained an orphan. At the same time, the boy was brought up for 11 years and called a son by his stepfather. But according to the documents, the man is nobody to the stepson. The teenager himself is sure that he is not an orphan, and his dad is mom's ex—husband. What awaits a ninth grader — a blood father's house or an orphanage?