Thank you for your advice and your support.

I have tried taking away her privileges and her toys and I make sure I ALWAYS follow through on whatever warnings I give her. Unfortunately, my 'mummy voice' has very little effect on her these days! I think she is just really pushing the boundaries these days and we need to hold very firm. It is incredibly frustrating and upsetting, though!

Last night she was warned, then sent to bed without dessert. There was much screeching, particularly because DS 5 was still up and was allowed dessert, but so far this morning she has been extra sweet and well behaved!

Thank you all for reminding me that I need to be consistent and surely this will soon pass. I do like like the idea of filming her, I think it would be quite effective with my little Miss.

OMG... she hasn't even reached puberty yet!! I think we're in for quite a ride...