Daff59
It is NOT possible to have a relationship of any sort with a narcissist.
You have been trained from early childhood to put your mother first and with your own needs and wants dead last. Setting and or making boundaries is likely very difficult for you mainly because you've been trained by your mother not to adopt any. She really does see you as an extension of her.
You are an adult child of narcissistic parent (and their associated enabler in the shape of your father). Women like your mother cannot do relationships so always need a willing enabler to help them. He has also failed you as his daughter here by failing to protect you from the excesses of his wife's behaviour. He has been all too willing to throw you under the bus and repeatedly out of self preservation and want of a quiet life. I would be having nothing more to do with him either going forward.
Re your comment:
"If it weren't for my dc I probably would consider nc or v limited but my kids love seeing them and are too young to understand any of the issues. On the flip side I really don't want them to be affected by any of my parents behaviours so am keen to shield them as much as possible. Just not sure how to strike a balance?"
It is precisely for the DC that I would adopt a no contact position now. Low contact often leads to no contact in any case and narcissistic types do not like boundaries at all. She will actively rail with your dad's assistance, against those and you will see her narcissistic rage/extinction burst again at first hand.
If a parent or relative is too toxic/abusive/difficult/batshit for YOU to deal with, its the SAME deal for the kids too. She in particular will harm your children in not too dissimilar ways as to how you have been harmed and this time the harm is again being done to your kids right in front of your very eyes. It can be a look., a pinch; she will express disapproval and in the one place they should feel safe too; their own home. Your children have and will keep on seeing you and their dad being disrespected and otherwise walked over in their home and what is also bad is that your parents could well use your children as a further way of getting back at you. These people may well have more disposable income and they will use that to buy the hearts and minds of your children. They will also adopt the golden child/scapegoat dynamic and or set one of your children against the others.
You're older and therefore more experienced which is the point of being the parent. The child is dependent on your good sense and protective wisdom. You're smarter than your child; use that to your advantage (such as using the distraction method). You are the final authority. This is not a negotiable issue. The kids doesn't get to decide on this one because they lack the understanding, wisdom, experience and good sense that, hopefully, you have. So don't look like you're unsure or open to quibble. You'll undermine yourself if you look anything but firm and resolved on it. Use your advantages as parent to smooth the effects of the cut-off. Over time this will all quiet down. Kids tend to accept what is. It will happen more quickly if you follow the above advice.
Most of all, do not operate from a fearful mindset. Don't be afraid of your children's possible, or actual, reactions. Don't be afraid that you are depriving them of something important by cutting off a set of grandparents. You are only "depriving" them of bad things. Reassure yourself with that truth. Family is not everything. Blood is not binding. You are escaping the Mob Family. What should connect us is how we treat each other with love and respect. This is always a good lesson to teach our little ones. If any part of you is unsure of your decision then, for Pete's sake, don't show it. Your resoluteness will go a long way toward reassuring your children that you are acting in everyone's best interest. If your children know that you love them, they are going to feel reassured that this decision is also based in your love for them. They will find an added sense of security to know that you, as their parent, are willing to protect them even at the cost of your relationship with your own parent(s). Rather than being fearful, see the plentiful opportunities in this. You are protecting your children from someone whom you've experienced as being abusive; you are reassuring your children that you are in charge and are watchful for their best interests (creates deep sense of security); you can teach healthy family values which include that family doesn't get a pass for abusive behavior; you can strengthen and reinforce the healthy relationships in your extended family. Kids are less likely to feel like there is a void in their life if you fill it with good things.
Cutting off from your narcissist parent is a good thing. No need to act otherwise. Your children will sense it is a good thing by how you behave. Model how you want them to respond and it is likely they will imitate. Don't be afraid of their questions. Kids are amazingly resilient and well-equipped to handle truth. Parents are supposed to protect their progeny. If your child doesn't agree with how you go about that don't worry. They will often disagree with your decisions for their best interests. Nothing new there. It is your job as parent to make the tough decisions. If you know it is the right decision then proceed with confidence. Showing confidence is a quality of leadership. As a parent you are supposed to be a leader. Lead...and they will likely follow.