Became known for her starring role as Ramona in the 2010 film adaptation of Ramona and Beezus. She has also appeared in such films as The Kissing Booth, The Conjuring, Reign Over Me, White House Down and Crazy, Stupid, Love. In 2014, she began playing Greta Grimly on the FX series Fargo and nabbed the lead role in Hulu's The Act in 2019.
She starred in over 100 commercials after getting her first job as a model for the cereal Life.
She made a brief appearance in Taylor Swift's music video "Mean." She provided her voice for the film Ice Age: Dawn of the Dinosaurs.
Her sisters are actresses Hunter and Kelli King. In 2019, she began dating Steven Piet. She previously dated her Kissing Booth co-star Jacob Elordi.
She played a young version of Marion Cotillard's character in The Dark Knight Rises.