A: The family should try and persuade her to re-think her decision to leave Islam. Try and convince her that Islam is the true and only way for her salvation. Continue such efforts for several months. If she persists being a murtadda, then warn her that she will not be accepted by the rest of the family. If this still does not shock her into re-entrying the fold of Islam then the whole family should ostracize her. She should be totally abandoned by all family members until she comes back into Islam. This is a sacrifice your family might have to make.
May Allah guide her and bring her back into Islam, aameen