Lum worked for several years as a
film editor for documentary filmmaker Spencer Nakasako. She's been mentored by Nakasako and documentary filmmaker
S. Leo Chiang. Lum directed the documentary short
Is Chan Still Missing? (2005) about the making of
Chan Is Missing (1982). The short was included on
Chan is Missing's 2022
Criterion Collection release. Lum's debut feature documentary is
Seeking Asian Female, a film about an older American man seeking to marry a woman half his age from China that he met online. The film is centered around Lum's perspective as a Chinese American woman, who document's the journey and serves as translator. The project was originally conceived due to Lum's interest in the real life complexities behind the
yellow fever phenomenon.
Seeking Asian Female was an official selection at the 2012
South by Southwest festival. Lum is the director and co-producer of the documentary
Try Harder!, a film about five high school seniors at the competitive
Lowell High School in San Francisco and their
college admissions journeys. Production began while Lum was working on a separate documentary about
tiger parenting,
My Tiger Mom, at Lowell High School.
Try Harder! made its world premiere at the
2021 Sundance Film Festival, which was held virtually during the
COVID-19 pandemic in the United States. It was selected to open
CAAMFest 2021 on May 13, 2021, as a
drive-in screening at
Fort Mason. == Personal life ==