I have recently (well about 7/8 months ago) got back in contact with my family after 6 years of NC. My mother was bloody vile when I was growing up and, from the age of 10 yrs old, I was in/out of care. My mother was EA, PA, MA and just an all round bag of shit as a parent. I went NC as, after 27 years, I realised that nothing I did would EVER be good enough. I was also SA by her exh, as was my dsis, but she gave me no support whilst lavishing love and support on my dsis. That ripped me apart (I was only 8 when we told her).
Then, about 10 months ago, I watched wait for it Jeremy Kyle and saw a story from an absolutely inspirational man whose mother was so abusive he ended up on ITU after a particularly bad beating when he was only 18 months old. He was put in care rightly so and he'd had NC for about 20 years. What he said was just amazing and made me think about my own situation....I had a 2 year old that neither parent had met, he would ask questions, and wondered if people can change.
I decided, after much soul searching (I always said I wasn't bitter but I realise now I was VERY bitter) and talks with OH, that I would see how it goes.
I can't believe how much she has changed. I am still incredibly guarded around her but I feel the guards lowering a tiny bit every time I talk to her. She was an atrocious parent but is a very good grandparent, my ds loves her. She appears to have chilled with age and has lots more patience. It also helps that we live over 100 miles away from her, as I feel the distance has helped keep space between us (I can imagine she would probably have been a bit over-bearing had we still lived close by). We see her on my terms, when it suits us.
I'm not saying that it's going to be the same for you but, maybe, give it some thought? My mother has said/done some dreadful things to me in my past but I feel so much better to have forgiven that and started afresh. I have even told her that I don't want to talk about what's happened (one of my reasons for NC was her refusal to acknowledge everything that had happened, to the point of calling me a liar and denying it) as it will rake up past feelings and I want to move forward.
I hope you find what's right for, only you can decide that 