Lots of sympathy, OP. Of course you’re not going to enjoy having such a child with you, even when you love her.
Though what you can do, I don’t know.
The really sad thing is that a child who’s been thoroughly spoiled and allowed to have their own way all the time, will be increasingly unpopular with everybody - except the doting parents.
The parents are absolutely not doing the child any favours at all, but I’m afraid parents like this hardly ever listen - they just don’t want to hear.
I dare say they will later wonder why their teenage daughter is a nightmare.
There was a schoolfriend of a dd who was the centre of her mother’s universe - not so much the father, but he was always overruled when it came to this child.
I once took dds away early from a party at her house, because we’d all simply had enough of her spoilt, entitled behaviour. Amazingly, one of the parents did phone to apologise afterwards! So it wasn’t that they weren’t aware - they simply never did anything to check it at the time.
She wasn’t very little, either - not long past primary school age.