She is a second-generation Chinese-American whose parents immigrated to the United States in the 1960s. A native of New York City, Representative Au is the product of a strong public school education, having attended P.S. 116 and Hunter College High School in Manhattan. She is a magna cum laude graduate of Wellesley College, where she graduated with a B.A. in Psychobiology.

Rep. Au currently works in Atlanta as an anesthesiologist. She received her M.D. at the Columbia University College of Physicians and Surgeons, and stayed on for residency training in both pediatrics and anesthesiology. She also holds a master's degree in Public Health from Columbia University.

In addition to her clinical work, she is public speaker, a published writer (whose work has appeared in The Washington Post, The New York Times, The L.A. Times, The Boston Globe, The Atlanta Journal-Constitution, The Atlantic and Slate, among others), the author of a medical memoir and a cartoonist. Her interests include enhancing quality health care access, improving public health communication and focusing on social equity as a key determinant of community health.

Rep. Au served as a member of the Georgia State Senate from 2021 through 2023, where she was proud to be the first Asian woman elected to that body. In her first term in the Georgia General Assembly, she was named 2022 State Legislator of the Year by Everytown/Moms Demand Action for her work on advancing gun safety and was named Legislator of the Year by the Georgia Chapter of the American Academy of Pediatrics for her strong advocacy on behalf of the health of the children of Georgia.

Rep. Au and her family moved to Georgia in 2008. Her three children are all products of the Fulton County public school system, and she lives with her family in Johns Creek.