Fiser was born in Newport, Arkansas, and raised in West Memphis. She received her undergraduate degree at the University of Arkansas at Fayetteville, and obtained her medical degree at UAMS in 1977. She completed her pediatrics residency and internship at University of Kentucky School of Medicine and held a critical care fellowship at the University of Florida College of Medicine. She joined the faculty of UAMS in 1981. Fiser is founder of the UAMS Pediatric Critical Care Medicine Section and Pediatric Intensive Care Unit at Arkansas Children's Hospital. She became chair of the UAMS Department of Pediatrics and chief of pediatrics in 1995.