On February 1, 2017, President Donald Trump nominated Brand to be United States Associate Attorney General. Her appointment was confirmed 52–46 by the U.S. Senate on May 18, 2017,and she was sworn in on May 22, 2017. The reauthorization of the 702 section of the surveillance law was a job assignment of the subject according to CNN. On February 9, 2018, the New York Times reported that Brand, along with her assistant Currie Gunn, resigned from the Justice Department. The NY Times article indicated Brand oversaw "a wide swath of the Justice Department" and helped lead the department’s effort to extend Section 702 of the FISA Amendments Act that "authorizes the National Security Agency’s warrantless surveillance program." On February 12, 2018, NBC News reported that Brand quit the Justice Department over fear she might be asked to oversee the Russia probe and was taking a position with Walmart as EVP of Global Governance and Corporate Secretary.
She was apparently deep into FISA. Wikipedia says she stepped down, but I suspect that she was pushed out as part of DS housecleaning.
Yes, I had just read the Wiki article before I posed the question... does not explain why - as Q puts it - she was removed.