Easy, ask the kid for the answer.
It took a while till I was able to trust myself to talk to my youngest child about her getting up and partying in the middle of the night in her brother's room - but when I did it was very worth it.
"during the day I am focused and busy and I can not think about my birth family and sad/bad things, at night I don't have any distractions and I can't not think about it and I do whatever I can to make that go away"
So now we are trying to set aside a chunk of daytime for her to do things that are all about her birth family. Yesterday before supper, she got out markers and paper and drew pictures of her sad cat who missed her, her old house that was upset because it missed her family and an upside down little girl - because that is how she feels right now.
Last night, she did managed to stay in her own room.
Yeah, yeah, I know that there will be more stuff coming down the pike, but I am going to savour this moment for a little while.
What a kid.