sometimes I think we blame everything on our situations and so often if you take a step back that is how things are even when Mum and Dad are together. Childrens behavious does come and go and all we can do as parents is to have rules, boundaries, ways of behaving that are acceptable and when they are not gently but firmly you pull the kids back into line . Consistency is key everyone knows where they stand. This is all about leading to a real sence of stability and security. What leaps out from this letter is a single parnet conundrum and that is overcompensating for the situation by as you say trying so hard to please her in every way . Do try to be the good in control parent that you would like to be even if you were still with her Dad. Children really do like boundaries and although it may feel like you are being kind by trying to please her it may have a slightly reverse effect.

You are very right to spend lots of time with her , 1 to 1 attention is great , making something together a cake for example , reading together , going on special outings together and so forth will all make her feel secure and so on .

And then the obvious talk talk talk talk about her time with Dad in a non questioning way speak positively about Dad and if it were me I would discourage and sweep to one side negative talking about any aspect of her time there even re the his new partner but talk up the time there. I would speak to Dad about how you can both reassure her as ever we suggest having a really good look at the co parenting section.

Also i might wait until she is back on an even keel before taking integration of your new partner up a gear , just keep it casual . But I am sure you know that all kids have spates of bad behaviour , it is often related to something that is upsetting them and it could be something very easy to sort out so try and talk to her when she isn't cross or being naughty to try and find out what it is , or ask her Dad to is it where she sleeps at his house , the food , does she want to sepnd more time on her own with him and not always with his new partner who knows she may be having a small problem at school

But do remember to stay firm on the boundaries and really try not to overcompensate

and also remember that this is friend type of advice and if you have serious worries and her behaviour is showing signs of distress then maybe your GP can refer you to an expert

All the best

Kate