Inspired at age seven by a local production of South Pacific, Mumford performed in high school plays and at Olympia's Capital Playhouse.

[2] While in college, she starred with Jesse Eisenberg in director Maggie Kiley's well-received short film "Some Boys Don't Leave".

[8] In February 2012, she was cast as the female lead in an ABC drama pilot titled Reckless.

[10] She starred alongside Billy Crystal and Ben Schwartz in the indy Standing Up, Falling Down (2019).

[12] In 2024 she appeared in eight episodes of Amazon Prime’s Cross as Shannon Whitmer, a woman abducted by a serial killer.