To dream of a family portrait represents how you wish to remember your past decisions. The family's behavior and background all reflect on how you see choices you made.
A happy family portrait reflects satisfaction with your past choices. You want to remember certain choices and experiences as positive. Not remembering yourself having done anything wrong.
Negatively, you may be in denial about choices you made or trying to replay the past in your mind completely ignoring the unpleasant truth. A wish to remember the past like nothing wrong ever happened.