Provide more info. Her age. Why you hate her. Her living arrangement. We better cam help if we know some of these things. Welcome and good luck.

Hello, i have the same feeling, I'm not sorry to say I hate her and her slutty mother. I dont want her at ky home every day when her mom is working and even on Sunday which is my only day off. I Just want to spend a nice weekend with my husband not with her. I can stand her at my home one or two days a week but not more. We still dont have our own kids, why should I stand this rude 8 year old girl. I love my husband and he loves me too. The only problem we have is because this kid. 

I'm new to the forum and glad I have come upon it while searching online with key words 'I hate my partner's child'. I have been feeling incredibly isolated in being 'alone' in this journey where you are actually 'hating' a 10 year old kid. Amongst my own social circles, work, family or friends, I'm the most tolerant, positive and easy going person around. But being forces to live with an unthankful, narcissistic and spoiled rotten 10 year old is turning me bitter inside. And there's no one I can talk to about this.
My partner and I have a 5 months old together but he priorities his daughter above all things because he feels guilty that her mummy and daddy is divorced and has to split her time between two households. Both of her parents essentially slave over her, she is entitled, arrogant and just not a nice person. I get it that she's just a kid, but that excuse just gets so old and illogical trying to explain away a 10 year old can't lift up a water jug to get water for herself, can't put the chips wrapping in the bin, can't shut the door behind her when she comes in, or even for not snap at her father for just generally caring for her. For example he asked her tonight 'weren't you playing hide and seek outside? What happened?' She snipped back in anger 'I don't  know! what's with the questions?'. He'll be dutifully preparing dinner for her (ahead of our dinner and for her only because there's a narrow range of food she would 'love' to eat) and she'll hold him to the 10 minutes he said it'll take to get ready (from when she shouted I'm starving! But if he prepares meals a minute before that, she is, in her own words, I'm not hungry!) She was telling him that it took 11 minutes! He said 'you don't have to talk to me like this' she said 'still! It's taken 11 minutes when you said 10'. These incidents just make me cringe so bad inside. I grew up with my parents who are void of affections and we as kids were thankful to have been provide food and shelter. I worked in my family business from a young age without pay because I was taught that it was duty to contribute towards the overall good of the family. And respecting our parents was just a rule of life. Now seeing this brat of a stepdaughter who is 'not happy' because her dad asked her to use her own pocket money to buy another doll (she has 9 already, the same dolls, she wants a 10th one). I asked my partner why does he think it's ok that she must has 10 identical dolls (in addition to the millions of other toys and items she possesses) he defences for her saying, oh you know, some people are into collectables. Basically you're telling me you're completely blind to the excessiveness and unreasonable demands of your whiny child. 

Im sick and tired of subjecting myself to the spare bedroom whenever the skid is around, I can't stand her but I'm always polite and friendly. Although on the inside I'm exploding and am contemplating leaving my partner even though we love each other very much. Now we also have a baby together which makes this decision much harder to make. 
Not in a happy place right now. But glad I can vent for the first time outside of my own headspace.