Hello, my parents divorced when I was 7 years old. My father remarried. I know he had 5 other children but I don't know anything else: I am not sure of their names, age, where they are, I don't even know if they are still alive because I had no relationship with my father after divorce. can I just ignore these half brothers and sisters and say nothing about them or is it misreprensentation? certainly I will never have to sponsor them because they are strangers to me. Please give me advice