I'm not really asking for advice but not sure what else to try to make things better. Sorry this goes on a bit.
My SD age 13 won't acknowledge me and its got worse since I married her fantastic dad. I've known her for 7 years, she was always cold toward me but I thought in time things would improve. Eventually they did a little, but since the wedding things have deteriorated. SDs mum is jealous and intentionally unhelpful and works against us - we have standards and are trying to bring SD up to be a respectful, balanced person but SDs Mum won't work with us on discipline (she thinks it's OK for SD to shout F Off in my face and says she doesn't care what goes on in our house) and won't remove privileges for really bad behaviour like we do, so we are seen as the bad guys.
SD is increasingly difficult (knowing her mum will back her up). She won't acknowledge me or talk to me. She leaves the room purposely saying goodbye Dad, goodbye Dog, but not me. She increasingly harps on about the times before I was in her life. She says the sky is green if I say it is blue. I cook her favourite food then she refuses to eat it. She is refusing to do anything her Dad asks her to and is rude. In addition, we have the usual teenage battles of too much phone time, only coming out her room to eat, refusing to engage in household activities when we give her the choice of what to do together, refusing to clean her room etc. She has vaped at 12, smoked joint and now just had sex at 13.
Her attitude is so awful toward me and her Dad that the atmosphere is now awful in my own home. She genuinely believes she can do what she wants in life. We have suggested she perhaps spends more time with her Mum but she doesn't want to (as she has a friend near our house). I have an older daughter so I know about teenagers but SD is is on a different level. We have never criticised her mum in front of her. I have only once tried to intervene in discipline when she was screaming at her Dad and that went very wrong. In 7 years I have always bit my tongue on her manners and behaviour and try to address them through her Dad. He has been good in trying to address her behaviour and they used to have a close relationship as he has spent so much time doing outdoorsy things with her, but now he is at a loss what to do, esp with the promiscuity this week. SD is already having counseling at our suggestion as she wont talk to us. I have always been kind to her and not get involved with discipline, but it has got a lot worse not helped by the fact her Mum says her Dad doesn't want to know her since he got married! (We are dealing with a jealous witch) We are therefore dealing with 2 children and just don't know how to make things better for all of us. She is with us every other week but I now feel like I don't want to be here when SD is , yet it is my house.