In the summer of 2014, I was sitting at my desk when I received an email from my mom. “She was being so naughty today,” Mom wrote. “She was jumping off a platform onto Mommy’s head.” The “she” in this message, I knew, was referring to the giant panda Bao Bao, who had been born at the National Zoo the summer before and who had been the subject of our emails, text messages, and adoration for nearly a year. At the time, I was 28 years old, building a career in Washington, D.C. My mom was 58 and nearing the end of a second career in labor advocacy in Oklahoma. Her first had been to raise me and my brother. But an abnormal chest X-ray was a harbinger of tragedy for our family. Three years later, she would undergo a lung transplant. She died from complications just two years after that. But back then, sitting at desks half a country apart, we each kept the Smithsonian Giant Panda Cam on our computer screens and sent …