My wife and I separated in 1991, at that time our daughter was about 3 years old. My wife had me sign and give up my parental rights to the child. I have seen my daughter off and on over the years only when her mother allows. My daughter just recently turned 16 years old. Her mother mistreats her and they fight most of the time. Several times over the past few years, her mother has thrown her out and she has come to stay with my girlfriend and me on several different occasions. This last time, now her mother requested her back and had to return to her mother's house. Now the child wants to live here with us. Since I have no legal rights to her, what legal defense do I have at this time, to make this happen?