I know you talk about secondary forgiveness, or forgiving someone who hurt a person you love. My question is this: Do you think it is legitimate to forgive the family member who is being hurt, who just lingers in the relationship without standing up for his own rights? This is making me very angry.
Yes, if you are angry with your family member for not seeking justice, then it is your choice whether or not to forgive that person. I realize that the one you are forgiving is not the victim in this scenario, but the person, in failing to exercise justice, is frustrating you and making you angry. This is sufficient to begin the forgiveness process if you are ready.
For additional information, see Why Forgive?