Your daughter may need some counseling. She's always been unusually insightful, a good therapist may be able to help her maintain healthy boundaries with your ex.
It hurts, I know - I'm dealing now with my adult children and their troubled relationship with their narcissist father.
Their is only one answer to this and it is so I could have YOU (D9) or KML(adult children)
I love you unconditionally. This is the answer she is looking for.