How Do I Get My Daughter Off Drugs Helping you help your daughter to stop her addictions

So this is a long and bizarre story.

I have known this guy for seventeen years an prior to our romantic involvement that started less than two years ago, I had no interest in him although he has always liked me.
We are in our thirties now. I have a 10 yr. old from a previous relationship. We have always been friends however had huge gaps in our correspondence because I had a child, he went away to college, worked nightshift and got married.
When we were 27(we are the same age) he got a seventeen yr. old girl pregnant and married her. It turned out to be a tumultous marriage. She physically abused him while he was in the military and living on base. She would hurt him and them call the police. She drank heavily, partied, cheated on him(even took out a loan for a lover putting up the family car for collateral). The biggest deal though was that she hid an entire pregnancy from him. They had already been married, had one child (who was 20 months old at siblings conception), and one abortion they both participated in. He was deployed part of the time. She didn’t even tell her identical twin or mother(with whom she is close) that she was pregnant even though she moved back home to live and work with him during part of the deployment. She sought no medical attention even though it was free. Her first baby had been born via emergency C-section. She told no one she was pregnancy and also did not seek alternative care. She also binge-drank vodka on several occasions. In fact she came back home w/him when she was seven and a half months, and attended a large party thrown by his parents for her older child, surrounded by multiple relatives and told nobody. Two months later he is in one of his training classes and is pulled out by a superior and told his wife is going into labor. He is not sure if this baby is his, she looks NOTHING like her sister but he raises her as his own.
She assumes he is involved with me one day(which he isn’t) and sends me multiple harassing and vulgar text messages.
Anyway, after the delivery, 14 months later he comes home for a three week leave on a fifteen month tour and she tells him she doesn’t love him anymore and wants a divorce. He is devastated but eventually relents. He and I are not involved at this point. She makes harassing phone calls to me. He asks her about it. She denies it.
They are now divorced. In 2008, they arranged a custody agreement for him to have the children five days a week. They come back from their mother’s home disheveled and often dirty. They look tacky(but she doesn’t), their hair is unbrushed and their nails overgrown with dirt underneath. This is amongst other neglectful behaviors.
His mother becomes very angry with the ex daughter in-law because she has taken them on weekends when he is in Iraq and witnesses their commonly unacceptable appearance and mannerisms. When son returns(after leaving military for good to be with his children), he and his mother have a huge falling out due to his renewed relationship w/his children now that he will no longer have to be away from them. His mother have previously hated his ex-wife due to the wife squandering thousands(of husband’s and mother-in-law’s money), hateful, disrespectful language from the ex-wife, and continued neglect of the children. His mother decided to have bad will against me because I was an emotionally supportive friend of his and as he spent more time with his children, she seemed to become angrier.
Well, I became pregnant. He and I now live together and have a child together. His ex-wife repeatedly calls her ex-husband for trivial matters even though she continues to neglect the children. She also repeatedly invited him for dinner. We reside in the old neighborhood in which I grew up. She invited him to go trick-or-treating with her(but didn’t invite me) and said to him she would love to go trick-or-treating in my neighborhood but didn’t want to run into me. He said nothing to her about this. She also has said disrespectful things about me to the children. He has said nothing about this. I have continually cared(meaning I take care of them)for her children by him in spite of the ugly way she has treated me. I have given them baths, have done their hair, dressed them, taken them to different activities, read to them. I don’t expect praise. I just know that all children need to feel loved. I also do not speak poorly about her to the children. It is clear she is emotionally unstable though.
The year where his mother stopped speaking to him, she then decided to like his ex-wife again.
I now have a baby with him(I know). I decided to let bygones be bygones and let her meet her grandchild. His mother trivializes the abuse the wife has enacted against her son and overlooks the neglect she enacts towards the grandchildren.
His ex-wife told him about the last time she had sex, how she was pregnant last year. It i
Blending a family is an investment, right? I have my problems with this guy(who I am planning on leaving). We have are own problems. However if he was hitting her, it would not be trivialized as just a “flaw”. When CPS, was called on her, the case was closed. People don’t like to think of women as abusers. I can see, as an abuse vitime, he appears to be relating to her the same way as in marriage-as a vitime-walking on eggshells. However I think he sends her mixed messages and he thinks he doesn’t. He spent Thanksgiving in her family’s home, he attended a birthday party with her, went to his child’s school event with her. I understand, that it is important to get along for the sake of the children, but she uses the children to have a relationship with her. She gets irritated that he doesn’t spend more time with her. How is telling him the last time she had sex have anything to do with the children? His mother abused him, so it isn’t surprising he stayed with a woman who did
I mean she uses the children to have a relationship with him. He doesn’t see it as inappropriate to text her at an odd hour or talk to her late at night, unrelated to the children. Also, he said when it comes to his mother offering her to spend the night, it is “none” of his business even though his Mom told him to tell it to her. Also, less than 1% of women conceal pregnancies to that degree, so it would appear to be more than just simply a “flaw”.
He has custody most days except she has them late afternoon Sunday through Tuesday morning.
He has custody most days except she has them late afternoon Sunday through Tuesday morning.