I found this book useful, 'Beyond Consequences, Logic and Control', by Heather T Forbes and B. Bryan Post. This is primarily aimed at parents of children with attachment issues. It is quite 'American', but I found some of it helpful. I think the Americans are years ahead of us in recognising the effects of attachment on the brain and behaviour.
I'm making a two assumptions here, firstly that your child has some kind of attachment issues, which she may not have, and secondly that you're not American .
For the record, I have some wonderful American friends!
This topic interest me, not because I am any good at parenting but because I have seen the 'naughty challenging' behaviour myself! I have a DD aged 8, a birth child, and my hubby and I are going through adoption process now.
I wondered, are the behaviours part of your child's problems from the past or the personality/fears etc that make them up?
If so the behaviour might be a chance to redress some of those things.
I will give you an example which might not apply at all to you but does in our family.
My DD is very sensitive so when things go wron,g or she is naughty, she gets totally upset and behaves badly, but actually as well as a consequence she also need to be reassured that even though I am unhappy about the bad behaviour I really love her.
I know we all probably do that to some degree with kids but for whatever reason my kid seemed to need that more than most. Once I worked that out I could manage to make the whole thing a lot less stressful. I am just offering that as one possible thought which may not apply to you at all.
Please feel free to PM me or ask me more if you want to.
All best wishes, it is hard but I also agree with other that it is just keeping going!
We started using 123 magic a couple of months ago. They get 2 minutes in the(open plan) hall if we get to 3. Their behaviour has improved no end and it's taken all the heat out of the situation if they are poorly behaved. I understand that this might not be the ideal solution in your situation. Most important thing (have to keep drumming it into DH) is that you are not allowed to lecture: as soon as the beeper goes they are back in the ring!
Do you think the honeymoon period is coming to an end? I think all you can do is stick with it, it is totally exhausting, but she is really testing her boundaries. I remember dd1 being like this, she was 2yrs 6 months when she came home. She had no boundaries all the time she had been alive, (even FC had set none) so she really did not like me installing good behaviour into her. We did a lot of inclusion, and I am ashamed to say now, we also used the time out step. Patience and a good sense of humour is required. Dd1 is now 14 and is a wonderful young lady, anxious but tbh I think that is pretty understandable. Good news that she wants to be in your arms. Best wishes.