Where to Watch Christmas Eve (1986)

Story of a well-to-do elderly woman, who befriends the homeless and volunteers her time with children, who learns she has an incurable illness and wants desperately to reunite her three grown grand children (who are scattered across the U.S. living their own lives), with their estranged father, her son. She hires a private detective to search for them so as to try to get everyone together on Christmas Eve.