Most parents first walk through the doors of Boston Children’s Hospital seeking answers about their child’s health. But until recently, when Mary Holleran arrived at the hospital, she was simply beginning another day at work. A nurse practitioner, she’s been on staff at Boston Children’s for more than a decade, much of it spent caring for children in the outpatient Hematology Clinic. Yet when Mary was pregnant with her older son, Liam, she gained a new perspective. “Liam was diagnosed with a type of spina bifida called myelomeningocele when I was 10 weeks pregnant,” she explains.