She also led a successful effort with then-Mayor Anne Rudin to introduce campaign finance reform to the city's politics.

[4] After graduation, she worked for five years at the Sacramento office of Orrick, Herrington and Sutcliffe, and later opened her own private practice.

[15] On December 21, 2015, Mueller rejected a First Amendment challenge, filed by crisis pregnancy centers, to California's law requiring them to provide notice to clients regarding the availability of abortions and contraception.

[19] The Ninth Circuit reversed the decision on June 29, 2023 saying Mueller "applied the incorrect legal standard" to the case, remanding back to District Court.

[21] Mueller also issued some of the earliest decisions interpreting the First Step Act in the context of requests for compassionate release due to the risk of COVID-19 filed by incarcerated individuals with comorbidities.