[2] Growing up, Marshall lived in Washington, D.C., the Chicago area, and finally Mill Valley, California, where she graduated from Tamalpais High School in 1987.

[3][5] In November 2010, President Barack Obama nominated her to serve as the United States Attorney for the District of Oregon to permanently replace Karin Immergut.

A subsequent inquiry by Willamette Week found she had been suspended by the United States Department of Justice (DOJ) pending investigation she had been in a romantic relationship with a co-worker.

Media reports in The Oregonian and Willamette Week claimed that Marshall had been sending numerous text messages and emails to a federal prosecutor under police protection due to threats against his life from the Mexican Mafia.

According to Willamette Week, the incidents had been an open secret in Portland, Oregon, for some time; its discovery by DOJ officials in Washington, D.C., prompted the suspension of Marshall and revocation of her security clearance.