A little something else. In the technology age if there are known or suspected person within a person past that someone would want to exclude from being able to get to them if that person was in a position of power and authority; that person could have been already under surveillance prior to being a trip to D.C. The arrival of this person, at the White House, may have been an afterthought as it was known this person may perhaps show up there?
Hmmmm....very good speculation! She could have already been on a list of sorts.