Adding a sibling help, please
My great-great-grandfather immigrated from Prussia, Germany. I do not know his parents' names because I suspect his lname was changed at Ellis Island. I just found his sister's name and would like to add her to his record as a sibling. When I go into details for him, I can add a child for him, or his parents. But not his sibling. Is there no way to do this given that I don't know his parents names? Thanks.