[6][11] Before becoming an actress, Rush began her career in her childhood and adolescence when she was discovered as a model in the United States, appearing in major campaigns and advertisements for fashion brands Polo Ralph Lauren, Gap, Tommy Hilfiger, and H&M.

[14] Rush co-starred, as Fiona, in the science fiction film The Giver (2014), based on the 1993 novel of same name from Lois Lowry, and directed by Phillip Noyce.

The film also starred Brenton Thwaites, Jeff Bridges, Meryl Streep, Katie Holmes, Alexander Skarsgård and Taylor Swift.

Rush played Hannah Fairchild, the "daughter" of R. L. Stine (portrayed by Jack Black), who teams up with her neighbor to fight the Goosebumps monsters.

[16] She was also cast as Ella Hatto, opposite Sam Worthington, in action-thriller film The Hunter's Prayer directed by Jonathan Mostow.