Brewton was born in Los Angeles, California. She is probably best known as the Mighty Thor-obsessed kid, Sara Anderson, in Adventures in Babysitting (which included Elisabeth Shue as Chris Parker), and as Shelly Lewis on one of the Fox Network's earliest shows, Parker Lewis Can't Lose.
In addition to these more prominent roles, Brewton starred in the movies Sky Trackers with Pamela Sue Martin and A Family for Joe with Robert Mitchum. She also co-starred in the hit film Back to the Future as Sally Baines, the younger sister of Lorraine Baines played by Lea Thompson.
Her television credits include 21 Jump Street, Highway to Heaven, Trapper John, M.D. and The Wonder Years. She also played Margaret Ann Culver in the short-lived television series, Lime Street with co-stars Robert Wagner and Samantha Smith.
Apart from her film and television roles, Maia Brewton acted in various theatre productions, most notably at the City Garage Theatre in Santa Monica, California.
A 1998 graduate of Yale University (where she was a member of Manuscript Society and Just Add Water), Maia is an attorney and successfully sat for the California bar exam. Maia married her partner, Lara Spotts, in 2008. The couple have twin boys, Rizzo and Calder.