Family or not - GET AWAY FROM THEM ASAP!
And if that's not possible then here are some suggestions on how to avoid conflict and avoid being the victim of their behaviors:
HOW TO DEAL WITH A narcissist:
Get as far away as possible as soon as you can!!!
Ignore them.
Be grateful they do not remember you
You keep reminding her that you are her child after all. Tell her that you are updated version of her!
You can become narcissistic afterwards, but you will not turn into a true narcissist. Stay away from him and go back to your family and hang around them for a while.
You leave. There is NO dealing with this sort of person. And seek counseling for yourself ASAP.
You are saying narcissist ex. If he is your ex he is not cheating on you and why would you care if he is your ex. Forget about this and move on with your life. If you think that this is cheating on you - better think again and also know that this will go on and on.
Offer the option to the Father. Tell him stop his attitude because it is affecting your relationship.
Sometimes not at first because a narcissist likes drama and likes to be around special people in order to feel special vicariously. But if and when she becomes too much for him to deal with he will leave. A narcissist really needs submissive women. Women they can dominate and control and get "Narcissistic supply" from....at heart they are insecure cowards!
There is every hope. Don't ever allow them to spend ANY time alone with the narcissist and protect them from their criticisms and reaffirm their self worth and value if the Narcissist gets to them. if things get bad, just stop taking the children. Their emotional, psychological and mental protection is paramount.
They will need family counseling to deal with the loss.
Yes, especially if that is how their brain "wired" itself to deal with that sort of behavior.
Everyone in the family joined a union