I don’t know wha to do anymore

I have a 9 year old stepdaughter that has been living with me for almost a year now. No kids of my own.It just feels like she doesn’t want to listen anymore. I have to repeat myself 100000000 times. She takes two steps forward then ten steps backwards in terms of improvement. Nothing works, grounding or taking things away and her dad says he’s already tried everything so I should stop yelling, grounding and taking things away. I know she is 9 years old but she knows the difference between right and wrong and I don’t know what else to do to make her accountable for her actions.I’m at the point where I’m thinking about moving out because I’m tired of the disrespect from her and lack of support from her dad. Ugh this kills me but like I said I don’t know what to do anymore. I’m tired. via /r/Parenting https://ift.tt/37gQdxj