My ex husband had NPD and also my mother,so I completely understand where you are coming from.
This is a character disorder and these people don't change.
I was with my ex husband for fifteen years and if anything he's behaviour got more bizarre as time went by.
Please get out of this relationship,before your mental health is completely destroyed.
If you can take your children with you,I would do so..take it from someone that knows..the damage done to these children,at the hands of an N parent can last for YEARS.
She will not change and if that is what you are hoping for,then you are going to hope in vain.