You do not have to fix the entire family system. You only have to draw your own boundary.
How grief and the death of a patriarch or matriarch force estranged members back together, often revealing long-buried secrets. Common Tropes: The Best and the Worst
Avoid the screaming match for the first two acts. Instead, use the slow burn. The loaded glance. The passive-aggressive comment about the casserole. When the explosion finally comes, it will be earned, not forced.
This character (or family member) absorbs all the tension to avoid conflict. They change the subject, laugh off insults, and clean up emotional messes. The tragedy? They are usually the first one to have a complete breakdown.