I want to adopt my 18 year old stepdaughter, how do I begin? We both are ready, I understand I don't need her bio-dad's permission (he has never met her and expressed he will not be in her life). I'm in Texas, if state law has anything to do with the process. I don't see the need for a lawyer if it's just a legal paperwork thing. I need to do this quickly to add some "wholeness" in her life and to me it just feels like the best thing I could ever do for her (I love being called Dad too).