DD1 is 5.
DD2 is 2
DD3 is 1
DC4 is in utero.
So basically DD1 had 2 1/4 years of being spoilt hugely and absolutely the main focus of me and DH attention. I still remember a bus ride with ehr the day before my due date with DD2, and just feeling resentful of this (much wanted) new baby who was going to radically affect our family dynamic (obviously that feeling evaporated immediately she was born).
DD3 followed DD2 very rapidly obviously, and DC4 close behind. So really since she was two it's been a pretty constant stream of new babies.
I try to give her special "big girl" time; before DD3 I would occasionally take DD1 out of nursery and go swimming with her, surprise her with stuff like that. DH and I make a "thing" out of big girl stuff, he takes her for late night walks, I take her for late night swims, I really do try hard to make special time for her (also work out of the home).
But I'm doing it all wrong, I must be. She's 5, but can act more like 9-10 in terms of attitude and way of speaking. And I have NO idea where she is getting it from; we don't watch TV, I am very strict about the books she reads, she hasn't been to school in 6 weeks so can't blame it on unsuitable friends, it must be me. And it's getting worse. Tonight she got very angry because it was DD2's turn to choose story CD for bed, had a tantrum and kicked duvet off. I ignored her,said goodnight and walked out, she ran after me and raked all her fingernails down my throat and chest. I was so angry I just put her back to bed and came downstairs; I didn't want to bellow, I wanted to deal with it sensibly and not when I was furious and in pain.
My DM (mental health professional) says she is hyper-sensitive and very bright, but that doesn't actually make being the best parent to her very helpful. I think DM blames me for having a large family in quick succession, she did say that she thought DH and I expect a lot from her in terms of dressing herself, washing etc. 
I've thought of asking my HV for some help, but don't want to get labelled as "struggling".
There was a parenting course I tried to get on, but it was run from 1330-1530 in the week and you couldn't bring pre-school DH, thus effectively ruling out anyone with school-age kids and no M/MIL on hand to help out 
Can anyone advise me please?