RAD and ODD?

Our placement, a 6 year old girl has been with us since August 2019 (10 months) We also have a 10 year old bio daughter abd a 5 month old bio son. I will never forget the first night she slept in our home. Before bedtime, she clung on to me for her dear life and didn't want to let me go. I told her "you'll be here for a while, don't worry. You'll be here tomorrow." Previously she had been placed in 15 different foster homes and had been in and out of the foster care system since 4 months of age. That morning, she woke up and said she had a dream where fluffy animals where hugging her telling her she was "finally wanted." See, the thing with my placement is that she is kind, polite extremely charismatic. She excels in a school setting and is kind to everyone who meets her. Unfortunately, that's not the side I see at home. At home she's mean, manipulative, clingy, defiant, she steals, she lies, destroys property and is physically aggressive. She was diagnosed with the Disinhibited form or RAD, which is an attachment disorder. This means she is very friendly with strangers and loves the hugs and attention but has not been able to form a genuine bond to us, her caregivers. To her, we are roles. We need to love her, we need to talk to her 24/7, we need to give her the food she likes, the toys she likes. We need to give her everything she wants or else, she defies us. In her head, if we do not give her what she wants, we are rejecting her and do not love her and that just validates her feelings. This placement has taken a toll on my 10 year old bio daughters mental health. Our foster daughter has stole from our bio daughter and has even physically hurt hurt her. One time our foster daughter choked our bio daughter because a dispute over a remote control. Being in theraputic foster care so we have been given tools to help manage her behaviors, mind you, we had no idea she has Disinhibited RAD when she moved in, there was barely anything on her file. Her therapist initially believed she had adjustment disorder. Lately we have no control over her. The honey moon phase lasted for it seems months. Quarentine and her knowing she was going to move in with Grandma brought all her behaviors back but in fill throttle. This weekend we surprised her with a poor party and the next day we surprised her with a day at the beach. Still, when we came back home she refused to go to bed. She simply said "no!" She wanted even more time with us. What am I supposed to do? I can't give her everything she wants, talk to her all the time. She already craves the attention and time I give to my bio children and husband and when I ask her to give me time she feels alone and rejected and acts out. She wants so much control, I have no control over her. I don't know how to get back to how things were with our foster child. I think its time to disrupt this placement. I'm so overwhelmed.