Hey there! 

 I could write a book about my whole story but I will shorten it up for you all. My Dh got full custody of my sd 9 over three years ago. From day 1 its been a struggle for me. I use to think it was me. Why was I having such a hard time being a stepmother? My dh doesn't have one problem with my 2 bio kids from a previous marriage. Well after years of trying I mentally and done. My sd ls a pathological liar, she hides everything, draws very concerning pictures is very sexualized for her age. She puts on an innocent front for her dad but he is slowly seeing. We have done therapy with 2 different therapists and it has not helped. I recently found out she has been watching sex videos. I was mortified. I know she needs professional help but im burnt out. My DH works alot and im a SAHM so he has basically thrown her on me since hes had custody. Ive finally put my footdown and its caused hell. My sd doesnt speak to me anymore unless she wants something. She will see me cooking and walk past me to ask her dad what I am cooking for dinner. She tells people im mean because i am not allowing her behavior she writes mean notes about me how she hates me. How do I disengage without causing a secene. Ive told him she is your child and you will do for her gets his feelings hurt because i dont want to be her "mother figure". My kids DO NOT cause problems or chaos and are respectful and love him so he just doesnt comprehend the problem. Ive tried. I know he needs to step up for sure but it is hard when he is the only one working he cant take off to do stuff for her. How would you disengage??