Is it normal/ the right thing to do, to want to cut all ties?

My family are totally screwed up emtionally/psychologically and seem to thrive off of game playing, bickering and fighting amongst themselves and I have finally had enough.

My mother -who I absolutely loath as she abused me as a young child both mentally as well as physically- had two children with my father (I am the first) and after he went off and married someone else, decided to deal with the situation by running him down, bad mouthing him, oh and......having six more children with him!

I started cooking and looking after the house, changing nappies and making up bottles when I myself was only just passed the stage of needing nappies and bottles! I was slapped around the face and called a bitch if I didn't do what I was told to straight away, as my mother could't cope with the children she produced, and obviously, with my being a child, I naturally, was the one who was meant to be taking my father's place in all of this!!

My father I have no respect for either, as he failed as a man and a father in my eyes. He left us with a person who was clearly not fit to look after a cat!! He would go off for months at a time and we would hear nothing.

My mother was also in the habit of lying through her teeth, to all and everyone. Turning sibling against sibling in order to get what she wanted.

She often told me, and with some spite, that my life would not amount to anything. That I would never find anyone to love me, would not secure a good job, and yet...

I now have a beautiful daughter, happy, loving and creative. My hubby is my soul mate and looks after the both of us, I have travelled. I have worked in both education and nursing, and have finally ended up living in the countryside, something I always wanted to do and will evetually move abroad to live. I am also an artist and photographer.

She on the other hand, has never even left the country, has no friends, no husband or man in her life to snuggle up with at night, telling her he loves her and that she is special and a wonderful mother.

The only children that she sees on a daily basis are socially awkward and can't maintain relationships as they are screwed up, can't hold down jobs and have moved back in with her as they can't afford to live anywhere else!! The eldest is 38, no girlfriend, no friends, no money to speak of.

Not only is she aware of the fact that she isn't respected or trusted by her own children, but that she has caused ill feeling between sibligs. Even so, people have chosen to behave quite badly towards each other.

Is it normal to NOT want to forgive them, despite knowing they have obvious mental health issues? Or am I being too harsh on them? Have others experienced the same, moved on, just cutting all ties, saying nothing? Did you find you could find closure regardless, or did you feel the need to get back in touch at some point?