This is what I don't understand about Rachael Brand she This is where she worked prior to being 3rd in line at the DOJ.

Privacy and Civil Liberties Oversight Board (2012–2017)

In 2012, Brand was appointed by President Barack Obama to serve on the Privacy and Civil Liberties Oversight Board (PCLOB).[17] She was confirmed on August 2, 2012 to a term ending January 29, 2017.[18]

Brand dissented from several recommendations included in the PCLOB's 2014 report on NSA's bulk metadata collection program under section 215 of the USA PATRIOT Act. She declined to join in the Board's view that the program was illegal as a statutory matter and argued that, in policy terms, it struck a justifiable balance between privacy and national security and, as such, should not be discontinued.[19] The Board, for its part, had recommended the program's termination.

What could she have done from February 1, 2017 to February 20th 2018?

Yes, she reauthorized the 702's - but what did she have to do with the email investigation?