I was sponsored by my wife 2 years ago and now decided that we want to get my son(from my first wife) but I am not eligible to sponsor him and need to wait for 5 years before I can sponsor a family member. He will turn 19 on February 2019 and won't be eligible then. Can my wife sponsor him even though they are not related by blood? I would appreciate if someone can give us an advice on what to do. Thank you!