Concerns on Home School Network

Let me explain this better than I did yesterday…
So, my boyfriend moved in with me over a year ago and shortly his teen daughter moved in as well (with my blessing and support). His daughter was having major issues with school, boys, social network inappropriatness, etc. She was living in public housing with her mother, three sisters (not my boyfriend’s kids) and step-father. Everyone got along very well in the beginning. Like one big happy family/friends kind of situation. I even went to get her kids from her all the time to give her a break. Well one day I took his daughter to her mother’s house to get her hair done and as usual, everything appeared normal. Before we came I told his daughter to bring her homework that she did not complete that weekend as school was the next day. While she waited to get her hair done, I told her to try and get some done so she can get it out of the way. Her mother says to me, that is my daughter and you have your own. I said I know, I was just reminding her to get her homework done for school tomorrow. (Of course she didn’t know that she even had homework and she once told me from her mouth that she was never hands on with her daughter when it came to school.) About two minutes later I was shocked when she began walking around the house talking about how “people” need to stop acting like they are her kids mother. She started cursing around the house, yelling at the kids, beat one of them, and kept making snide remarks directed at me. The whole time I said nothing. I texted my boyfriend to let him know something was wrong and that I might need to leave and for him to pick his daughter up. He calls her and she immediately curses him out so he texted me to take his daughter and leave. After that point I NEVER exchanged words with her again. I let him know that I want him to have all further dealings with her. So months later his daughter began to act up really bad. Skipping school, getting caught with boys, etc. So we began punishing her and reaching out to the school for assistance. So she said she wanted to move back with her mother and all of a sudden she didn’t “like” me. I wasn’t bothered because typical teenage response to “step-parenting”. Anywho, the mother caught wind and began threatening him to send her daughter back to her. He eventually caved. He took her to her mother. Shortly after I began receiving threatening text messages from his BM. She even threatened to do things to us until we broke up. Very childish so I never responded. After a week his daughter cried to come back home with us, so now she’s back. After she returned the mother has still texted me and he finally said that he wanted nothing to do with her on a personal level. I told him that I never wanted a personal relationship with her again as well. I also stressed that I didn’t want her kids to come to our house anymore because she began using her kids as pawns. Telling them evil things about me and then they would come over my house acting very funny towards me. She also said she didn’t want his daughter living in a house with me so I feel that her other kids should stay with her then! Don’t send those kids to my house if you don’t even want me around the daughter that she and my boyfriend share. He is not the father of any of the other kids. His daughter is the oldest so he knows those other kids, but he didn’t raise them. Now he said he wanted one of her daughter’s to come over our house because he felt sorry for her. Mind you he feels sorry for every child. We have loads of kids at our house due to his work with the boys n girls club. He doesn’t understand how I feel and thinks I’m being mean to her kids. I told him that it goes beyond the kids. I need his BM to show respect to me first. We don’t have to be friends, but she must respect me. Until then, I don’t want to be mixed in her life which includes her kids. Am I wrong’