I have had these feelings for over 30 years, but I need to say something to someone. DH is away and she has yet again made me mad, sad, angry and near to tears. What she actually did this time is irrelevant, I won't bore you, it's minor in the grand scheme, it just brought all my feelings to the fore.
I despise her, every fibre of her being.
She is thick, selfish, inconsiderate, lacking in any sense of reality, has no manners, has no respect, has absolutely no idea about responsibility, has ripped off my parents her whole life, speaks without thinking, and last but not least, and worst of all, thinks she has some kind of bloody god given right to now be involved in my life because I have children. She didn't get in touch for years, but once my DC arrived she was all gush gush gush, oh I am such a wonderful aunty, let me at them let me at them let me at them.
She has no genuine interest in them other than how it reflects on her, makes HER seem important, gives HER someone to boss around and be pathetic near. They are still young, but they are cottoning on to her, and I don't want her to have any involvement or influence in their life in any way shape or form. She is pure poison.
I have hated her all my life, if I had my way, I would never ever see her again. My DH hates her even more than I do.
My Mum and Dad know how I feel, obviously it makes them sad, but they say I have to put up and shut up, that she somehow is entitled (fuck off she is) to be involved in their lives, and have basically said, if I block her from me and my immediate family, then they will have no choice but to not see us either. They can't stand her either, she is a drain, financially, emotionally and physically on their whole life. They are mid to late 60s now, they don't have the strength either to deal with her or to fight with her, she just runs rough shod over them now.
I worked hard my whole life, found a wonderful man, love where we live and two fantastic children. Life is good, hard work, but good. SHE, the she devil, hardly did a day's proper work in her whole sodding life, was bought a house (yes a HOUSE) for which she doesn't pay the mortgage or any rent. She has an almost brand new car now too, all her bills are paid, she fucks about, gets drunk and just pisses her money up the wall on the latest phone/clothes and my parents still feed this monster.
I am not in the slightest jealous of her, if you are thinking I am. I would be mortified to be 35 and totally dependent on my parents. I own everything I have, it is all mine/ours. Every last bit. I made my own career, found my own husband, created my own life around all that and never asked for a thing.
She is everything I despise rolled into one person.
I never want to see her again. My family says I have to. My DH says fuck her, never see her again. My Dad even said to me that I had to "compromise" regarding putting my children first, I had to take my sister's feelings into account, even if I didn't want to. WHAT THE FUCK, he has kids, doesn't he know your kids always always come first?
But I cannot bear that my DC would lose touch with their GP's.... that makes me very very 
Rant over. Sorry it's so long. I couldn't stop. I've never written all this down before. 30 years of hurt has just burst out! I am so angry I am actually shaking.