I have a 17 year old Stepdaughter who will turn 18 in 4 months. I have a 15 year old biological son. I have lived with my fiance for about 4 years. Her biological mother really doesnt have much to do with her. Their relationship is strained and she is not allowed to live with her mother (her mother's choice). Her father and mother divorced when she was very young. He remarried another woman and was with her for 9 years. His second wife would not give any attention to his daughter, only her own.
Knowing this I have done the best I could with giving her attention, giving her some of my belongings (clothing accessories etc) that she liked or was interested in. I have bought her things and encouraged her to succeed. Many times I was harder on my son than I was her. Both children are responsible for chores (cleaning their rooms and after themselves) and getting good grades in school and we do the rest. My family shows her love and showers her with affection and gifts just as they do all the other kids. My family and I have shown her more love and affection than her own biological family with the exception of her father and grandmother (on mothers side).
In the last 6 months, she has become a terrible person. She disrespects her father one minute and in the next she is idolizing him in a very uncomfortable way...to everyone around. She had posted terrible things about me on social media, she has posted pictures and videos of her drinking and smoking and doing drugs on social media. She lies to us constantly. Her and her friends harass my son at school. She was caught at a party with drugs and alcohol and at that point I took away all her phones and internet devices except the one she uses for school. Her dad has had talk after talk with her. I have had talk after talk with her and our relationship is now strained at best. She hides in her room and will not come out unless she absolutely has to.She no longer eats with the family and her father and I no longer try to get her to eat with us. She has blamed me for everything. She now says that her father is only a "dad" when I am not around and I am taking him away. He actually spends more time with her than he did any other relationship. I do not bother him when they spend time together because I think it is important. I have spent time with her as well as my son one on one so they get my full attantion. She refuses to acknowledge anything I have done for her. When her father brings it up, she says it was just me being nice to her to get to him. He has asked her to try to fix the relationship and talk to me, she refuses. She has been disrespectful to both of us and has ruined just about every relationship she has except with her grandmother. She has disrespected her fathers friends when they come over as well. People she has known most of her life.
I have told him I will never ask him to choose between his daughter and I. I will not, however, put up with negative attitudes and disrespect in my own home. I have told her she needs to get a job and change her attitude by the time she turns 18 or she will need to consider living with her mother. Her mother will not take her. Her father will not kick her out if she does not comply because he is afraid she will fail and become homeless. I told him that is a choice she has to make, change or get out. She would always be allowed back in as long as she changes her behavior and shows us respect. It doesnt have to be permanent. He does not want to make her leave. I have told him that I understand and I would not ask him to choose, therefor I will leave if she cannot at the very least TRY to work on the relationships in the house. I will not leave the relationship with him, but I refuse to live like this. I am at my witts end and so is he. I have tried every parenting technique Ive read about and researched but it seems nothing is working. I feel like a terrible person because I do love her but I do not like her as a person at all. I have tried writing her letters and talking to her but at this point I am so beyond hurt that it has turned into resentment. I feel like she is too old to be acting like a spoiled brat. I do not want to feel this way and I want to save the relationship but I cannot do it alone. I am trying to keep this brief but this is a huge part of the current situation. Any advice?