Dear Amy: An old school friend of mine posts often on Facebook. Her updates are mostly upbeat, entertaining, and harmless. Over a decade ago, both her brother and her father died of unexpected illnesses. A sad situation, of course. Her mother and one remaining sibling are still alive, and they are close. However, all these years later, she posts about her father and brother on FB regularly, noting, “Today would have been H’s 55th birthday.